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Department of Chemistry
Texas A&M University
College Station, TX 77842-3012
Department of Chemistry
Texas A&M University
Ross St @ Spence St
College Station, TX 77843-3255
Department of Chemistry
College Station, TX 77843-3255
© 2016 All Rights Reserved. Department of Chemistry, Texas A&M University
Guidelines for Keeping a Laboratory Record
The following is a general description of how to keep a proper laboratory notebook. Requirements for different teaching, research, clinical, or industrial labs will most likely vary. Some institutions/labs will require less stringent record keeping, others will hold you to a very strict protocol. A well kept notebook provides a reliable reference for writing up materials and methods and results for a study. It is a legally valid record that preserves your rights or those of an employer or academic investigator to your discoveries. A comprehensive notebook permits one to reproduce any part of a methodology completely and accurately.
Outline of procedures
Choosing a notebook
For most purposes you may select a bound notebook, quadrille-ruled. A teaching lab may require tear-out duplicate pages for making carbon copies. An engineering or industrial research/development lab will likely require a specific type notebook with prenumbered pages and places for date and investigator’s and supervisor’s signatures on each page. Pads of tear-out graph paper or spiral bound notebooks without pre-numbered pages are not acceptable. It must be impossible to tear out a page without leaving evidence. It is safest to select something that is clearly labeled as a laboratory notebook.
Preparing the Notebook
Please use a ball point pen for all entries, so that the marks will not smear nor will they be erasable.
Put your name, a telephone number and/or address, and project name or course number on the outside front cover of the record. Put that same information on the first page inside, or on the inside front cover. If your notebook does not include a prelabeled table of contents section, then reserve the next several pages for a table of contents by labeling the top of each page as Table of Contents and numbering each page. If your notebook does not have prenumbered pages, you may wish to use lower case Roman numerals, as in a standard publication. Next, number the next several pages with Arabic numerals in sequence, and you are ready to begin recording data.
What to enter
Above all, it is critical that you enter all procedures and data directly into your notebook in a timely manner, that is, while you are conducting the actual work. Your entries must be sufficiently detailed so that you or someone else could conduct any procedure with only the notebook as a guide. Few students (and not that many researchers for that matter) record sufficiently detailed and organized information. The most logical organization of notebook entries is chronological. If a proper chronological record is kept and co-signed by a coworker or supervisior, it is a legally valid record. Such a record is necessary if you or your employer are to keep your rights to your discoveries.
Depending on requirements set by a teacher, superivsor, company, or whatever, you may not have to confine your notebook entries to lab notes only. On the other hand a student might record your class lecture notes, lab lecture notes, ideas, questions, library research notes, and notes that are part of any pre-lab preparation. The bare minimum entries for an academic lab course, for each lab study, should include title of the lab study; introduction and objectives; detailed procedures and data (recorded in the lab itself); summary.
We usually record a lot more information in a laboratory notebook than we would report in a research paper. For example, in a published article we don’t report centrifuge type, rpm, rotor type, or which machine was used. However, if a procedure is unsuccessful you may want to check to see that you used the correct rpm or correct rotor. Perhaps the centrifuge itself was miscalibrated. You would need to know which machine you used. In a research paper one does not report which person performed which tasks, because such information is useless to a third party. However in the notebook it is important to note who was responsible for what procedure. Again, you may need such information to troubleshoot your experiments.
Someone else may need to consult your notebook sometime, so please make your entries clear and legible.
When you make your first entries of the day, start by entering the date, writing out the month or abbreviation for the month (e.g., 5 Apr ’04, or April 5, 2004, but not 4/5/04). The use of numerals only can cause confusion. For example, in Europe the day comes before the month. Thus April 5, 2004 would be written as 5/4/04. When you start each new page of a notebook enter the date next to the page number. Each page should be numbered and dated consistently. Most of us use the upper right corner of each page for date and page number.
Depending on how your notebook is designed you may choose whether or not to use the backs of pages. If you leave them blank, put a corner-to-corner line through them to void all blank spaces. Some people use the backs for rough calculations, then void remaining blank space. You might also decide to save space (and trees) and use both sides of each page. Obviously you cannot use both sides with notebooks that are designed to make duplicate copies. In situations where you turn in duplicate copies to a supervisor, you obviously must start each new set of entries on a new page.
Write a title for each and every new set of entries. Distinct sets of entries should be separated by using informative headings and by leaving a single space or two between individual sets of entries. Specific information can be more readily located that way. For a new laboratory study, write down a very brief introduction to the study, and list the objectives. If you have a specific hypothesis, write it down. The object is to make it completely clear what you intend to do.
Record everything you do in the lab, even if you are following a published procedure. For example, if you started by obtaining a quantity of tissue from an instructor, then write down that you obtained tissue, describe it, note how much, what condition, etc. How much you write down is up to you, but any relevant information should be there. For example, it doesn’t matter much if you received a chunk of liver in a red ice bucket or a black one. However, it does matter that the material was on ice. If you change a protocol in any way or decide between alternative methods, then the correct information must be recorded in the notebook. For example, a protocol for tissue fractionation may recommend centrifugation at 9400 x g, but we may decide to use 12,000 x g in the lab. The correct g force must be noted.
If you make a mistake, put a line through the mistake and write the new information next to it. Never erase or obliterate an entry. When you finish a page, put a corner-to corner line through any blank parts that could still be used for data entry. Every bit of every page must be legible and filled, either with information or with a mark that voids the section (see examples).
When you have finished a project, summarize what you have accomplished. You don’t have to draw conclusions, just indicate what sort of data or observations you collected, samples you saved (and where and how you saved them), or any other relevant information that wraps up the study. For a continuing study keep the summary extremely brief. In fact, if the notes are well organized and it is obvious where the study left off, you need write nothing more than "To be continued. " Summaries help maintain continuity. They indicate where the work left off and how it might resume.
Doing two things at once?
Simply use your best judgment. You could divide each page into columns and keep your two records side-by-side. You might date two consecutive pages, keeping both records separately. In either case, when you leave the laboratory for the day cross out any unused parts of a page that precede the last entry.
What if you need more than one page for a project? With continuing research, that will always be the case. Proper use of continuation notes makes it possible to follow your path through a long experiment or series of experiments without having to leaf through every page of your notebook.
For example, let’s say you labeled some protein samples with the radioisotope S-35, ran a gel, and placed the gel in a film cassette in order to produce an autoradiograph. During the two days your film is in the freezer, you devote all of your time to a cloning project that is part of an unrelated study. After you put your film cassette in the freezer, simply write Continued, page ___, then enter the date and title of your other project, and continue to record information.
When you resume work on the protein samples, enter the date, write Continued from page ___, and enter your autoradiography results. This way, everything you do in the laboratory is recorded chronologically, yet someone interested in following your progress could start from the beginning and follow every procedure on just that one study, from start to finish.
Are things getting too sloppy?
Perhaps your data records are scattered throughout the notebook, and you would like to summarize them. Go ahead. You may re-enter tables or figures any time you wish to organize your work a bit better. To prevent confusion over duplication of data you may put a line through a table or figure you intend to re-draw, initial and date the change, and note the page on which the re-organized data can be found. Just don’t obscure any of the original entry.
So far you have been advised to record each step you perform in the laboratory, regardless of whether the procedure is published somewhere. However, once you carry out a procedure, you can refer to that part of your notebook, and only note changes you make. For example, the first time you prepare a sequencing gel you should write down the exact formulation, how you mix the gel, how long you let it cure, etc. The next time, just refer to the name of the procedure and the appropriate page(s) of your notebook.
Suppose you enter raw data into a computer and have a printout with 400 pieces of data. Or, suppose you generate a graph using a software program. You might even have a silver-stained gel that you wish to refer to frequently, or a fluoroescence photomicrograph that sums up your results nicely. Some investigators prefer to attach such materials to the notebook itself, but too many such items make a sloppy notebook and can stress the binding. Loose data should be kept in a separate folder or notebook, with location noted in the book.
Table of Contents
Record all entries in the table of contents as you go along. You can organize it anyway you like but it is advisable to include multiple levels in a table of contents, that is, indicate where a new study starts and include subheadings for specific parts of a study, methods, sets of data, etc. The idea is to enable someone (such a supervisor, grader, or yourself a year from now) to find anything quickly. List each set of entries with dates and page numbers. If you are seriously anal-retentive, you might record every experiment in chronological order, then use the remaining blank space to cross reference the contents experiment by experiment.
For a teaching lab you might list each and every set of entries made in your notebook, in chronological order, including complete and informative titles. Examples of sets of entries include an introduction, a summary, a set of procedures for a specific preparation, a complete data set, calculations for diluting samples or preparing assay standards, etc. A grader should be able to find any specific entry quickly, without flipping through pages.
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The laboratory notebook in the 21 st century
Detailed note-keeping is a prerequisite for, if not a key component of, scientific discovery. An unrecorded experiment is lost to the world even if it sparks a great idea in a scientist’s mind: Additional work is needed to reproduce and confirm the original observation and to test the hypothesis by novel experimental strategies. Hence, a detailed record of the experimental setup, observations, and analysis is a crucial requirement for presenting a new discovery to the scientific community.
“An unrecorded experiment is lost to the world even if it sparks a great idea in a scientist’s mind…”
For centuries, scientists have been using paper notebooks. However, the digital revolution has changed every aspect of data handling: Acquisition has become automated, primary data exist in a huge variety of formats and require vast memory space, and analysis increasingly uses sophisticated software. While electronic note-keeping has become state of the art in the pharmaceutical industry, it is by far not the standard in academic life-science laboratories. In fact, digital record-keeping has been controversial in academia, and hence, its implementation has been lagging.
We argue that many academic laboratories will soon abolish the current precarious mixture of digital data and paper-based annotation. We see three main reasons for this trend. First, the vast majority of the data generated by a scientist will be in digital form that has to be documented and archived; however, the paper-based laboratory notebook does not enable convenient documentation of folder structures and data paths. Second, ongoing efforts aim to standardize experimental protocols and data formats in order to improve their general comparability and re-analysis of data, which make standardization more attractive for scientists. In fact, standardization is a prerequisite for using an electronic laboratory notebook (ELN). Third, long-term data storage, an essential component of good scientific practice, easily turns into an absurd exercise when detailed and standardized annotations (metadata) are missing. Many institutions worldwide are therefore considering electronic note-keeping to support good scientific practice (http://lib.guides.umd.edu/ELN, http://academictech.doit.wisc.edu/ideas/electronic-lab-notebooks).
In 1985, Howard Kanare wrote a classic book Writing the Laboratory Notebook that has taught generations of scientists how to record their work 1. The book features a whole chapter about the electronic notebook that carefully lists advantages and disadvantages. Many of the disadvantages are now anachronistic, but the main arguments against the ELN remain technical issues and involve time requirements, costs, and security. Any laboratory interested in going paperless will have to make substantial investments into developing templates for notebook pages, protocols, and reagent stocks. The financial consequences of introducing an ELN are not limited to obtaining software licenses but include dedicated servers, backup systems, and IT staff. ELNs may introduce new error sources and security risks that did not exist for paper notebooks.
On the other hand, there are many substantial advantages of going paperless: In the long term, the use of templates for similar processes should considerably save time. Modern search functions can greatly aid the preparation of reports, manuscripts, and presentations. From the perspective of the PI, an ELN offers huge potential in standardized data collection and facilitated data management. Classically, a student who graduates after generating research data for years leaves several paper-based notebooks and a digital folder structure that contains raw and analyzed data on the group server. Without laboratory-wide nomenclature rules on how to name files and how to record data paths, it becomes extremely time-consuming to realign experiments and stored data. In fact, this material will often only be used in case of an emergency—failure to reproduce previous results or suspicions of scientific misconduct. Since entries into an ELN have to be standardized for each group, they would automatically provide a searchable description of all data stored on the group server. Ideally, the ELN would enable efficient use of data by successive generations of students and postdocs, would maintain technical knowledge in the laboratory, and allow detailed reconstruction of individual experiments.
There are a variety of software products available. In order to select the optimal solution, institutions or research groups interested in going paperless would need to perform a careful analysis of their workflow to define their specific requirements. Decisions revolve around from where the software is run (local or company server), where the data are stored (locally or in a commercial cloud), who can access the data and documentation of all changes made. Critical issues are the design and administration of templates for standard operating procedures, data exchange with specified equipment and servers, search functions, and an inventory management system, for instance, for reagents or constructs stored in freezers. These aspects are critical because laboratory members will not use the ELN if their workflow becomes more tedious or time-consuming.
Templates within the ELN are electronic forms that guide the scientist through the various steps of an experimental protocol and make it convenient to enter all the specific information while providing standard values by default. A major advantage of the ELN is the inclusion of all digital data via links—hence the software must be capable of linking to any storage location that a research group uses. Another major asset of the ELN is full digital and fast access to stored information. The respective search algorithms must be powerful and reliable to fulfill this expectation. A product-requirements document is essential to assess these and other desired features. In most cases, the final decision regarding ELN software will ultimately rely on a test by some members of the laboratory.
The laboratory notebook is the scientist’s permanent companion. It lies open on the bench next to reagents and experiments and is being carried around from room to room wherever its owner conducts experiments. This mobility allows for continuous recording. To achieve the same degree of mobility for the ELN, a tablet PC is possibly the best choice. In principle, any device capable of displaying a website could run most ELN software. However, empirical testing of the specific combination of software and tablet in a standardized case scenario is necessary as certain combinations of tablet PCs and browsers may greatly reduce functionality. In addition to choosing the optimal software and hardware, the ELN has to be integrated into the local network infrastructure with associated storage space that can be securely assessed to enter data using different hardware devices.
Switching to an ELN requires motivation and substantial time and financial investments. But once adopted, the ELN can benefit the scientific community as a whole by catalyzing the development and use of metadata schemes. In fact, digitalization at the source, that is, right at the experiment, could greatly aid reproducibility, data quality, long-term storage, and the lifetime and impact of research data.
Even more importantly, metadata—data about data—are becoming increasingly essential. In the experimental sciences, metadata would describe the parameters of an experiment, such as the temperature at which a reaction took place, the name of the scientist performing the experiment, or the details of the equipment and reagents just to name a few examples. Metadata aim at fully describing the context of how the data were acquired to make them reproducible, interpretable, and amenable to re-analysis. Metadata are also key to assembling useful databases and to comparing large-scale experiments.
“… many academic laboratories will soon abolish the current precarious mixture of digital data and paper-based annotation”
Traditionally, metadata have been recorded in paper-based laboratory notebooks implicitly rather than explicitly. Use of an ELN is therefore a great opportunity to make metadata explicit and to record them in the only way they can be useful: as detailed and as standardized as possible. Practically, this means that the templates and forms which research groups design as they customize the ELN should enable, encourage, and—where appropriate—enforce metadata recording. Once useful metadata schemes for standard procedures exist, we anticipate that some of them will spread in the scientific community because using them will benefit individual scientists (for instance when publishing their data), research laboratories (when training new laboratory members), collaborating research groups (when sharing or comparing data), and whole research fields (for instance, when referring to the literature or databases).
The simple example of Western blotting, a standard procedure in molecular cell biology and many related disciplines, illustrates how metadata could help to solve a number of problems in current scientific practice. Proteins are separated by gel electrophoresis, transferred to a carrier membrane, and visualized by an antibody-based detection technique. A Western blot yields information on the size and abundance of a protein in complex protein mixtures, including variations owing to differential gene expression or posttranslational modifications. While good standard protocols for Western blotting exist in books and on the Internet, it is surprisingly difficult to find even two laboratories that perform this method in exactly the same way. Moreover, as it is a standard technique, publications rarely describe the experimental details of how Western blotting was performed. Thus, many relevant details of the experiment, such as the gel system or protein transfer system, will never be accessible to other scientists. The poor documentation of the immuno-detection part of the procedure is an Achilles’ heel of modern biomedical science. The indiscriminate and unprofessional use of antibodies has confused whole fields by myriad misinterpreted or irreproducible experiments involving antibodies 2 and wasted time and money. Poor documentation accounts for a large part of this confusion.
A standard metadata scheme for Western blotting represents an ideal way for recording all this information in a concise yet versatile manner. The metadata can immediately be used as Supplementary Material for publishing and enable future inclusion into databases as appropriate (http://www.antibodypedia.com). If provided as a routine template in the framework of an ELN, such a metadata scheme would be integral to the experimental workflow. Hence, it would not have to be painstakingly created at the time of publication to avoid the deposition of another poorly documented blot into the scientific literature.
Good scientific practice mandates that data should be kept for at least 10 years 3,4. Many laboratories retain all the documentation to reconstruct experiments and to revisit the associated primary data much longer—but tracing and using it can be anything from time-consuming to impossible. In the worst case, the group server turns into a ‘black-hole’ of key information without truly making it accessible. The ELN can be used to address this problem by virtue of simultaneously arranging and structuring the recorded information into person- and project-based, searchable records without requiring additional work while entering the data. Each scientist in the research group can use the ELN for daily record-keeping as if using a paper-based notebook. In addition, project identifiers connect the described experiments to a particular project, which allows to store, organize, and retrieve all records in a chronological or project-based fashion. All primary data will be directly linked to these records—either as files uploaded into the ELN database or as links connecting to network-attached storage space, that is, the group server that will now no longer be a ‘black-hole’. Data structure, such as names of directories or levels of organization, and access rights for individual files have to be carefully adapted to the ELN as the main record-keeping tool. At least the outline of a pertinent data structure and access rights needs to be designed by the respective PI and the more long-term laboratory members such as laboratory managers or senior technicians. An intuitive and time-saving concept to data management and backup is the only way to ensure compliance by the whole team.
“…the evolution of scientific methodology […] makes it increasingly difficult to keep all relevant information in the respective notebook”
Many scientists collaborate with colleagues from other laboratories, often funded by joint research grants. Thus, research data from these projects are usually relevant to others beyond the own laboratory; on the other hand, it also raises the question of protecting unpublished results. Still, sharing of data seems to be a problem in some research areas 5. As soon as several scientists from different laboratories begin to store their data electronically on one server, sooner or later the question of ‘whose is it?’ will come up. Normally, issues of intellectual property will be covered by local legislation, and the data policy can refer to this framework but it would also need to include a separate data policy signed by all PIs in a joint project. By default, scientists should only have access to their own data in an ELN. For sharing data with other colleagues, they can have assigned additional rights, such as only reading or reading and writing. PIs of individual laboratories will have to decide on who can share the data generated by their team members.
Although there seem to be many advantages inherent to an ELN, every new technology entails new challenges. These can arise from the infrastructure, storage media, software, or human error. The arguably biggest challenge is the change of data formats over time; a problem that of course does not affect paper since it has been around for 4000 years. All data have to be migrated to new media or new formats once certain standard formats for texts, images, or other forms or data become outdated. The software provider’s concept or solution for data migration during software updates should be an important aspect when choosing ELN software.
Many academic laboratories still prefer the paper-based laboratory notebooks 6. However, the evolution of scientific methodology, which almost exclusively relies on computer-controlled equipment that generates digital data, makes it increasingly difficult to keep all relevant information in the respective notebook. Furthermore, modern concepts of sharing and comparing publicly funded research necessitate digitalization. Digital recording at the source is the most effective and scientifically most appropriate way of further developing and implementing these concepts. While the transition to completely digital note-keeping represents a formidable challenge that requires substantial investments into infrastructure, software, and staff, it also represents an opportunity to revive and where necessary reinforce a digital version of the standards and skills that Howard Kanare so successfully disseminated.
This work was funded by the German Research Foundation (DFG) within the grant for the Collaborative Research Centre (SFB) 1002 on Modulatory Units in Heart Failure, subproject INF. We thank Johann Bernhardt, Anne Clancy, Detlef Doenecke, Stephan Lehnart and David Schwappach for helpful discussions.
Writing the laboratory notebook
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Writing the laboratory notebook
A laboratory notebook is a chemist’s most valuable tool. It contains the permanent written record of a researcher’s mental and physical activities from experiment and observation, to the understanding of new phenomena. A laboratory notebook is a researcher’s diary. The act of writing the notebook forces one to stop and think about what is being done in the laboratory. After the experimental data is recorded, the researcher begins to study, analyze, evaluate, and interpret the notebook. New ideas and questions are written down and the laboratory notebook evolves into an expression of the Scientific Method.
There are important legal reasons for keeping a good notebook. A laboratory notebook is admissible in a court of law for patent claims. In recent cases of suspected fraud, the FBI confiscated laboratory notebooks as physical evidence. In industry as well as at the University, a researcher’s laboratory notebook is property of the company/University. In companies, it is witnessed and signed each working day. The proprietary information the notebook contains should not leave the building.
In this course, your laboratory notebook will contribute to your grade. I will review your notebook periodically throughout the semester, and it has to be submitted to the TA’s along with your final report. You should be prepared to have your notebook collected at any time. The main criteria for evaluation will be, "Does the notebook clearly tell what was done?" And, if the notebook was sent to a laboratory in Hammerfest, "Could they understand what was done and repeat the experiment?"
Your notebook should be bound and numbered continuously throughout. The first few pages should be left blank for the table of contents. All entries should be recorded with a black or blue ball-point ink pen. The key to writing a good notebook is simple clarity: Clear layout, clear descriptions, and good penmanship. A notebook which is filled with scribbles and scrawls will waste your time when you look for something and may actually be misleading. The following is a general guide with comments on how your notebook should be organized for each experiment. It was modified from, "Writing the Laboratory Notebook" by H. M. Kanare.
Begin reporting an experiment by recording the date and title of the experiment on the very top of a new page. Below this a statement of the purpose of the experiment should be listed. You should reference the source of the experiment.
A few simple sentences to state the work that is to be done. A flowchart, outline, or list of steps may be appropriate. This section is mainly for readers so that they understand what you are doing. It is good practice to include notes on safety in this section.
3. The Observations and Data Section.
This is the heart of the experiment where you actually record observations that you make during the course of the experiment. These notes and data will allow you to test hypothesis and apply the Scientific Method.
Record the data as completely as possible and leave interpretations for later. Don’t be embarrassed about writing down mistakes or accidents— if you drop your product on the floor, record in your notebook "Product was accidentally dropped on the floor; used paper towels to recover some of it."
Write down everything!! Your results hinge on exactly what you do, not how nicely you sugar-coat them in the notebook. A few general notes which you should specifically pay attention to in this course:
• Record all information necessary to unambiguously identify chemical reagents and other research materials, including the manufacturer and the age or expiration date. If you repeat the experiment, use "Protocol according to p. xxx, but with the following modifications. " and then list whatever was different from the protocol you are refering to.
• Note whether water was distilled (singly or triply) or deionized, and the pH.
• When using an instrument, write down completely the model and manufacturer. Are you sure the instrument is running properly? When was the last time it was checked or calibrated?
• Use proper names for labware and vessels. Was the sample weighed in a dish crucible, beaker or flask? What kind of flask ?
• In what sequence were reagents mixed? Was "A" added to "B" or vice versa? How precisely were the reagents measured? Was the balance significant to 0.01 gram or 0.00001 gram? Use significant figures!
How long did it take to go from "A" to "B"? Did the color change occur immediately or after hours, minutes?
• Was the laboratory ambient unusually dry or humid? Hot or cold? Why?
• Include drawings of experimental apparatus or devices. A good drawing can save you several pages of writing and be very clear to other readers. Be sure to indicate a relative scale. Keep drawings simple and to the point. Draw the TLC, clearly indicating SM (starting material), R (reaction mixture), and C (co-spots). List chromatography conditions.
• Make corrections by drawing a single line through the incorrect data. Be sure to leave the unwanted entry legible, it may turn out to be correct.
• When graphing data make sure all axis are labeled with units and tick marks. Give the graph a simple title. Include error bars and note on or near the graph where the raw data that were used to plot the points can be found.
A final point is the inclusion of the actual raw & spectral analysis data. Many advisors encourage researchers to catalogue and store their data in separate files or binders. A researcher would then have a separate file for each compound that he or she made containing IR data, NMR data, spectroscopic data, etc. This data is then catalogued and cross referenced to the laboratory notebook. Alternatively, you can paste the spectroscopic data into the lab notebook at the appropriate position.
Begin this section with a heading such as "Discussion" or "Data Evaluation" or some other phrase that clearly separates this section from the data and observations. This section gives you the opportunity to ‘think in the notebook.’ This section can contain calculations, charts, graphs, rearranged data or interpreted data. New ideas should be recorded here. How could we improve this experiment? An idea may occur only once, and only briefly: catch it while you can and record it onto the page.
In the last section of your notes you should summarize the goal of your work, what was done and what was learned. Typically this can be done in a few concise sentences.
The Laboratory Notebook
The Laboratory Notebook 1,2,3
Authors: B. D. Lamp, D. L. McCurdy, A. E. Moody, M. C. Nagan and J. M. McCormick
Last Update: February 28, 2014
The laboratory notebook is perhaps the single most important piece of laboratory equipment. A scientist’s notebook may be directly entered as evidence in court, and as such may be worth millions to a company in patent litigation. While you may never be in a situation where your notebook is worth a million dollars, good record keeping is essential in all scientific research. In an academic laboratory, the consequences of poor record keeping are wasted time as you repeat the experiment, or simply failing the exercise. In an industrial laboratory, inadequate lab records ultimately cost the company money, either in the cost of time and materials or as the result of legal action. In either case, the cost to the responsible employee is their job and all possible future employment. Thus, adequate record keeping will be stressed in all chemistry laboratories at Truman.
There are many different sets of rules for keeping a laboratory notebook, 3 which range from the very elaborate rules followed by industrial chemists to the simplified rules listed below. Not all of the points given here will apply to all courses; your instructor will point out modifications to these procedures in his or her syllabus or in the laboratory. No matter what guidelines you use, the goal is to produce a record of a scientific endeavor that is understandable to a knowledgeable reader and which can be used to repeat the experiment and, presumably, get the same results.
Notebook Format and Rules
Laboratory records are to be kept in a bound notebook (i. e., secured with glue), not a spiral notebook or a loose-leaf binder. The pages are to be consecutively numbered. No pages are ever to be removed (except for the copies produced by duplicating notebooks).
All entries are to be made directly in the notebook in black or blue ink. Everything related to the laboratory work must be recorded in the notebook in an organized and neat manner (if it cannot be easily read, it is not adequately recorded). It is critical that the material is intelligible and understandable to the notebook author and any trained chemist who reads the records, attempts to reproduce these results, or endeavors to finish an incomplete analysis. This concept is often known as “traceable” in the industrial world.
It is unacceptable under all circumstances to rewrite (or “copy over”) an experiment in the notebook outside of lab. It is also unacceptable to type up portions of the laboratory notebook in a word processor and then attach the printout to your notebook. Plan your activities in the laboratory so that all information is properly entered into the notebook while you are in the laboratory.
Include in the notebook a complete description of the work performed, all reference materials consulted, and ideas that you have related to the work. There should be no loose scraps of paper in the notebook. Graphs, charts, spectra, or spreadsheet analyses should be affixed to the pages of the notebook with tape or glue (to both the original and duplicate pages of duplicating notebooks). Label the space where this material is to go with a description of the item and the results it contained. This way, if it is removed, there will be a record of it. Make no notes on the inserted material.
On the first page of your notebook are written the name of the class, your laboratory section and your name. It is also a good idea to put contact information (e. g., your phone number or email address) here, in case your notebook is lost. The next two pages are reserved for a table of contents (some notebooks come with a table of contents section on the inside front cover, or as a separate, removable sheet; these should not be used). The words “Table of Contents” are to be written at the top of these pages. The first entry is to be the table of contents itself. An entry is made in the Table of Contents for each experiment when it is begun. This entry includes the title of each experiment and the page number on which the experiment begins.
You may wish to dedicate one page to a “Preface” in which you describe yourself and the contents of the notebook. Another item that is sometimes included is a page titled “Abbreviations and Other Useful Information”. These items must be completed before the first laboratory session.
If you are using a non-duplicating notebook, one usually uses only the right side pages. The left pages are reserved for minor calculations, notes of no consequence to the experiment and notes that refer to material found elsewhere in the notebook. In academic laboratories, especially in teaching laboratories, this rule is relaxed as a cost-saving measure for the student. Please check with your instructor on which protocol he/she wishes you to use.
If a page is skipped, a large “X” must be drawn across it. The page is then initialed and dated. While generally frowned upon, you may skip a line as needed to separate sections. There should be no unused empty space on a page, except for the printed margins. Treat large blocks of blank space like a blank page (this assures the reader that no information was added later).
At the top of each page write the title of the experiment that matches that in the table of contents. At the bottom of the page place the date that the last entry was made on that page, your printed name and signature (or initials).
If an error is made, draw a single bold horizontal line through the error so that it can still be read. Write the correct information to the right of the incorrect entry and have a short accompanying explanation of the reason for exclusion. Never use whiteout or completely obliterate the incorrect entry.
Do not copy any information from the notebooks of former or current students. The only exception is when working in a group, and only one member of the group recorded the data during the experiment. In this case, you must indicate in your notebook that the results were copied from the other person’s notebook. Write the recorder’s name and the page number from which the data were copied next to the copied data.
In general, the notebook should be arranged in chronological order, so that when one experiment ends the next one begins. In an undergraduate laboratory this is very easy to do, but as you progress in your study of chemistry, things are not always so well-ordered. If you must start a new experiment before another is finished, you simply note on the last page of the unfinished experiment the page on which it will be continued.
Arrangement of an Experiment in the Notebook
Each experiment’s record includes the following sections: Title, Statement of Purpose,Background, Procedural Outline, Results, Calculations, Discussion of Conclusions and Error Analysis, and Summary of Results. Each section should be clearly labeled with the underlined words indicated below. Sign and date each page as it is completed. The Title,Statement of Purpose, Background and Procedural Outline sections must be prepared prior to the laboratory period (click here for a checklist of what to do before lab).
Title: This should include the experiment’s title, your name, the name(s) of your lab partner(s), and the date the experiment was begun.
Statement of Purpose: Clearly and concisely (two or three complete sentences) describe the purpose of the experiment, including the general method that will be used and anticipated results. Do not begin a Statement of Purpose with the phrase “The purpose of this lab is to. .”. Don’t resort to stock phrases; be somewhat creative. The pedagogical purpose of an exercise is not the same as the Statement of Purpose. For the “Determination of Density” exercise, the pedagogical purpose is to learn about precision and accuracy, and the statistical treatment of data. But your statement of purpose might read “The density of a copper block will be determined by two methods: (1) from its dimensions and mass, adn (2) from its mass and volume, as measured by water displacement.”
Background: This section contains more information on the goals of the experiment, the methods used and the procedure followed. The content of the Background section varies with the type of experiment being performed and the requirements of each laboratory course. Check with your instructor about what to include, but in general the Backgroundsection must include:
1) reference(s) to the procedure that you are using following American Chemical Society guidelines. This reference should contain the full title of the article, or the title of the book and the name of the experiment. 2) balanced chemical equations for any chemical reactions that you will be performing. Mechanisms are to be included, when appropriate. 3) a table of important physical properties of all the materials (starting materials, solvents, and products) with which you will be working. Be sure that you have thoroughly read the experiment before preparing this table so that it includes all the chemicals that you will use. The following information must be in this table: the name of the compound, its molecular structure, and its molar mass. Other properties that may be important are melting points, boiling points, density, optical rotation, etc, depending on the particular laboratory exercise. Textbooks, laboratory manuals and library references (such as the CRC Handbook of Chemistry and Physics, the Merck Index, and the Aldrich Catalog of Fine Chemicals) are good sources of information on chemicals and their properties. There are some internet resources that also contain the same material. Care should be taken in consulting internet sources because there is often no independent scrutiny of these sites. 4) record any hazardous properties (flammability, toxicity, etc.) of the substances that you will encounter in the exercise. The Merck Index and the Material Safety Data Sheet (MSDS) for a chemical are excellent sources of this information. Both are available from the library or the stockroom.
Procedural Outline: This section is a brief (this section should not be more than one or two pages long, at most), but complete, description of the steps taken to carry out the experiment. It is not a rewrite of the source material (e. g., laboratory manual, textbook or journal article); use your own words, You may use a bulleted list for the steps. At your instructor’s discretion, you may not be allowed to bring the source material to the laboratory. So, be sure that your procedure is complete.
Before beginning the Procedural Outline, divide the pages that will contain the procedure into two parts by drawing a vertical line on the page, approximately 3/5 of the way across the page from the left-hand margin (many notebooks already have this line drawn for you). Record the procedure on the left-hand side, and any modifications or procedural notes on the right-hand side. You do not record your results on the right-hand side! Results are recorded in the Results section.
Read the experimental section for the exercise before recording any part of the procedural outline in your notebook. This will make writing the outline much easier and minimize errors. As you read, think through the manipulations that are required and re-read sections that indicate particularly hazardous or important steps (usually denoted by “CAUTION!“). Once you are sure of what you are going to do, go back and write out a step-by-step procedure in your notebook.
Results: This section does not need to be completed before you come to the lab, but you may want to prepare blank tables for recording data. Include in this section a listing of the reduced data (e. g., tables), all graphs, spreadsheet results, and spectra. Unlike theProcedural Outline, this and all following sections may use the entire right-hand page. A common error is to forget to leave space for the graphs (a hand-drawn graph should take up most, if not all, of the page so as to maximize the results’ precision) and other items (e. g., spreadsheet output) that will be prepared as part of the exercise.
All data should be recorded in this section in chronological order. Include all measurements made (with proper units and correct number of significant figures) and any important observations noted when performing the work. When observations are recorded in the laboratory notebook, they are always written in the passive past tense. So instead of “I saw the solution turn green”, one writes, “The solution turned green”. In general, personal pronouns (e. g., “I,” “we”) are not used in scientific writing (the overuse of personal pronouns is taken as a sign of arrogance and the passive is thought to sound more objective). The observations are always written in complete sentences.
When possible, set up tables for repetitive data before coming to the lab. Thinking carefully about the data that will be taken should allow you to prepare a data table, which, although difficult to accomplish for the first few experiments, will save time and space in your lab notebook. The use of tables will make it much easier for the reader to assess your methods and results.
Information on the chemicals and instruments used in the experiment are also included in the Results. For a chemical, the name of its manufacturer, its purity, and the lot number of the chemical are recorded, if this information is available (look the bottle’s label). It is easiest to record this information when a chemical is first mentioned. For example, “A saline solution was prepared by dissolving 5.00 g NaCl (99.999%, Aldrich, Lot # 56390-BX) in 500 mL of distilled water.” The identity of all instruments used must be recorded, preferably including serial number, model, manufacturer, and any information on the calibration or settings used. Remember that you want to have enough information in your notebook so that you can easily repeat this measurement, if and when necessary (e. g., you find a mistake). If the instrumental data were saved on disk, include the filename(s) with the data. (More Info)
Calculations: An example of each calculation performed to reach the final reported answers should be shown with the units clearly shown at each step. For most exercises in a teaching laboratory, only one example of each different calculation needs to be included. Be sure to label each calculation and parallel the order in which the calculations appear in the procedure. You may want to set up the calculations before coming to lab to maximize your laboratory efficiency.
It is sometimes acceptable to include calculations in the Results section as needed. This is usually done in research situations where you need to make a calculation that you did not anticipate at the start of the experiment, but is sometimes allowed in upper-level courses where the laboratory exercises are not “cookbook.” Check your instructor’s syllabus, or ask him/her, for the format that you are to follow in your course.
If you made more than one measurement on the same phenomenon, calculate the average and standard deviation. Perform other statistical analyses as instructed. When an accepted or theoretical value is available, calculate a percent error. Include the output from any programs used to perform these calculations, and the filename under which the data were saved.
Discussion of Conclusions and Error Analysis: Summarize your results paralleling what you set forth in the Statement of Purpose, compare them to the expected results and try to place them in context (either in the larger field of chemistry or what you have done in class). This is not a long section; it may only be two or three pages long in the notebook. The key to a good discussion section is to concisely cover the important points.
Do not write things like “I liked this lab”, “This lab went well” or “This lab was successfully completed”, and do not use personal pronouns. Take your time and put some thought into your conclusions.
The discussion should try to pinpoint various specific sources of error encountered from the standpoint of the most likely determinate and indeterminate errors in the procedure. Once you have identified a source of error in your measurement, evaluate how it affected the result, and then suggest how this error could be minimized or eliminated. Simply attributing everything to “human error” is insufficient, and will be graded accordingly. Some labs won’t have numerical results to discuss, but you can still indicate sources of uncertainty and how they could be, or were, minimized. To help you learn how to organize your discussion, brief outlines for the three types of exercises usually encountered in undergraduate chemistry laboratory exercises are given below. The types are:
1) exercises with a primary focus on measurement, 2) those which are focused on the synthesis of a compound, and 3) those exercises which require you to observe and report on physical phenomena.
Many aspects of the discussion section are the same in all three, but there are subtle differences that you should appreciate. These outlines are meant only as guides; you will need to adapt them to each particular experiment. Some experiments may incorporate components of each of these three broad categories. In that case, you will need to write a conclusion that combines the three types of discussions.
Outline for Measurement Experiments
A. State the results and associated statistics. -If an accepted value is known, assess whether the result is accurate (use a calculated percent error). -Identify what factors lead to a decrease or increase in accuracy. -Discuss how the accuracy could have been improved. -Is there evidence for systematic or gross error? What is the source of that error? -Is the result precise? (use the standard deviation and/or confidence limits) -State what factors limited the precision (use propagation of error results). -State what experimental methods or practices maximized the precision. -Suggest ways that the precision could be improved. -In the absence of a true value, discuss whether the precision allows you to have any confidence in the accuracy of the result. You may be able to qualitatively assess the accuracy of your results (e. g., if wood floats, then its density must be less than water’s, do your data support this conclusion?). B. Evaluate the experimental procedure. -Was the procedure sufficient to provide an accurate and precise result? -If not, how could it be improved? C. Discuss whether the result(s) is(are) reasonable in comparison to known values or in the context of similar measurements.
Outline for Synthesis Experiments
A. Report the properties of the prepared material and what methods were used in the characterization. -Do your results match published properties? -Compare the published and the experimental properties to assess purity. -In the absence of published values, evaluate the purity based on the material’s properties. B. Report the percent yield. -Is the yield reasonable? Compare to the literature or others in class. -Evaluate the factors and experimental techniques that gave a less than, or better than, average yield. C. Evaluate the utility of the synthetic procedure. -Does the reaction give the product in high enough yield? -Is the material sufficiently pure? -Is it not too complicated or lengthy? -Suggest improvements.
Outline for Reporting on Physical Phenomena
A. Describe the system that observed and how you probed its properties. Use sufficient detail so that reader can clearly picture the experiment, but avoid being overly verbose. B. Describe what you saw. -Did you see what you expected to see, or were there differences? -Are the results reasonable, based on what you know about chemistry? C. Try to explain any differences between what you observed and what you expected. -Was the difference because of your experimental procedure? If so, how could you modify the procedure to change the result? -Was the difference a result of reactions or other things that you didn’t consider initially? If so, how will you need to change your assumptions to accommodate the new data?
Summary of Results: For measurement and synthetic exercises you will need to include a final table summarizing the results of your experiment. For a measurement exercise this table should include each individual value used in the establishment of the average (check with your instructor if you have more than three or four individual values), the standard deviation, and the confidence limit. For a synthetic exercise your summary table should include the percent yield and the measured physical properties of the new substance. Once the Summary of Results has been recorded, sign and date the experiment.
Labels for Products: If you prepared a substance in the exercise, you must place it in a properly labeled bottle and give it to your instructor. The bottle label must include: