Keeping a Laboratory Notebook
In many fields – especially the medical and engineering professions – records must be kept meticulously in various forms. Perhaps the most familiar form is the medical chart that doctors, nurses, and other health professionals must keep for each patient. For scientists, the equivalent document is the laboratory notebook, which is considered to be the primary record of their data collection.[1]
If laboratory notebooks are not kept properly you may find that your future work cannot be confirmed by others and will have to be retracted, even if you actually did them. They have been known to be subpoenaed in court, and requested if others question your results.
An example of a problem caused by this can be seen from this example. Taira and his students at the University of Tokyo, who specialized in RNA research, landed in hot water because of the lack of laboratory notes. A member of his group failed to keep laboratory notes, and as a result, it was determined to be irreproducible and not credible.
Another problem is that, especially with larger-scale projects, it is not uncommon to write papers or reports based on experiments that may have been completed weeks or months ago. Alternately, you may find that you need to remember how you did a certain experiment which you may have done last year. In either case, keeping an organized laboratory notebook will help you recall what you have done and report the results without redoing the experiment.
As a course for science/engineering majors, we aim to ensure that you have gotten into the habit of keeping good lab notes. Even if you are going into the medical fields rather than pure science, the concept of rigorous note-keeping is also found in medical charts.
The Basic Rules
A common misconception is that the notebook needs to be neat/tidy/etc. That’s false. It needs to be legible so people can figure out what you did – but good handwriting and neatness isn’t actually required! Rather, what is required is that the data is recorded as you conduct the experiment.
The golden rule for this is that your laboratory notebook should be a complete record of what you did. A good student in your class should be able to repeat your work and compare their results with yours based solely on what is in your notebook.
As this is a chronological, formal record, the following rules apply:
- All entries must be dated. While each experiment should begin on a fresh page, you should feel free to continue on multiple pages for a given experiment. If an experiment spans multiple days, just put the second date in the middle of the page (where you begin on the second day)
- If you run out of pages in your notebook, you must get a new one. You may reuse an old laboratory notebook from a previous semester provided you have pages remaining.
- You are not allowed to skip pages in your laboratory notebook – use your pages from the first to the last, in that order. If you slip up, then cross out the blank space.
- Notebooks are your primary record. Therefore, be sure to record data as you go along. Data cannot be recorded on scrap bits of paper or notepaper and then transcribed into your notebook.
- Keeping it neat is not a priority; however, it must be legible.
- In order to prevent the carbon sheets that are not being written on from being scratched, place the periodic table attached to the notebook directly under the yellow page on which the duplicate copy should appear.
What to Include in your Laboratory Notebook
These are the expectations in the general chemistry laboratory. They may vary in other courses and in research.
Before the Lab Period
Before you enter the lab, you should have the purpose and procedure sections for the experiment prepared. Some people also prepare data tables for their experiment in advance. Whether you do so is up to you, entirely.
Near the beginning of the lab period, your instructor will walk around and inspect laboratory notebooks to ensure that it is properly prepared.
Purpose
What is the aim of your experiment? What are you trying to find out in this experiment?
Generally, a hint of this can be found by reading the objectives of the experiment. However, you should review the introduction and procedure of the experiment to see what you are trying to do.
The purpose statement should typically be no more than a sentence or two.
Procedure
Essentially, what you need to do is to paraphrase, in note form, sufficient essential details that an “A” student in this class can do this experiment without recourse to the laboratory manual. This is also an opportunity to be sure you understand the procedure; you are more than welcome to ask questions of your instructor before (as well as during) your lab period.
Before writing up your procedure, please check Canvas and previous class notes/announcements for any changes to the experimental procedure that may have been announced. If any changes to the procedure are announced in class or were decided as the experiment proceeds, you should record these changes in your notebook.
Note-form is acceptable and that full sentences are not required. The use of abbreviations is acceptable. Sketches and flowcharts are also appropriate.
You need:
- An outline of the procedure – enough detail to reproduce the process.
- Critical volumes, concentrations and pieces of equipment must be described. However, you don’t need to write down approximate volumes of reagents used (when the amount of reagent used really doesn’t matter) or the exact details of the standard glassware used unless it affects the accuracy or precision of the experiment.
During Your Lab Period
Be sure to record all data and observations as you collect them into your lab notebook. You should record sufficient detail such that you have sufficient information to complete your laboratory report.
While this information typically will be the same as that required to complete your report form, sometimes there are other things that need to be reported. It is always safer to record too much information than to record too little detail.
Never write down anything on scrap paper or your manual; that is just plain wrong and will always lead to mark deductions.
A few other points:
- If you make a mistake, cross it out neatly (no whiteout; one should be able to read under the cross-out).
- Results should be recorded to the correct number of significant figures and include units.
- Make sure that things are clear enough that someone else reading the notebook can understand it. Remember, while you are writing the lab report up (typically) in the same week, in real life you’re writing it up months (occasionally years) later.
End of Lab Period
At the end of the lab period, after you have cleaned up your work space and disposed of all waste, you will present your lab notebook to your instructor for inspection. Your instructor will look at your notebook and make comments, based both on what is in the notebook as well as what your instructor observed during the lab session. The instructor will grade, sign and date your notebook. If an experiment takes more than one lab period, then the instructor will simply sign and date your notebook.
After you have completed a given experiment, turn in the carbon (yellow) copies for the experiment at the front bench before you leave.
- Even though the term is "laboratory notebook", it is not restricted to experimentalists! As a computational chemist, I keep a laboratory notebook as well for my computational work. While some groups now use electronic lab notebooks, these typically have specific logging/security requirements and are not acceptable for this class. ↵
