8 Top Tips on How To Keep a Lab Notebook
A lab notebook is an accurate record of your scientific work as well as an essential document to any Good Lab Practice (GLP). The lab notebook acts as a primary source to a scientist’s experimental activities and includes details of experimental procedures, observations and interpretations. Consequently, a poorly-kept lab notebook could lead to the loss of crucial data, unreliable interpretation of the scientific activities, and could even cause problems in getting data published. All of this could potentially cost you precious data, time and money, and might affect the reproducibility of the experiment.
Lab notebooks come in various forms, from the “traditional” paper lab notebooks to Electronic Lab Notebooks (ELNs). This guide will focus on the “traditional” paper notebooks and will share 8 important fundamentals to help any busy scientist keep an accurate and comprehensive record of their experimental work.
We most probably need some kind of disclaimer, “This guide is designed to provide general guidance to scientists, it is not intended to replace any documents or protocols your lab has in place.”
Get yourself a good notebook
Use a bound (stitched) A4 lined notebook, with consecutively numbered pages. The numbered pages make it easier to identify if the pages have been removed or exchanged and helps when referencing the experiments – I will explain this further in the next point.
In order to protect the contents from accidental or chemical damage, ensure the notebook has a robust cover.
Commonly, the first two pages of the lab notebook are reserved for the table of contents. These pages should be updated regularly with the title, experiment ID, page and date of each experiment; the table of contents will come in handy when you want to find details of past experiments.
Use a simple numerical identification system for experiments
It is customary for successive notebooks to be characterized by assigning a number (i.e. I, II, III, etc.) to the front cover of the lab notebook. This primarily helps to create a clear identification catalog for each experimental notebook entry and secondly helps to individualize the work conducted by individual members of the team.
For instance, the numerical labeling system shown in the example below, can be interpreted as an experimental study starting on page 35, of lab notebook III, and performed by the scientist with the initials E.O.
Example numerical labeling system: E.O.III-35
This unique identifier can also be used to assign a title to spectroscopic data, linked to the respective experiment, e.g. E.O.III-35_HPLC.
Writing the date span on the spine of the notebook (e.g. 2016-2018) will also help you locate your experiments when stored or archived on a shelf.
Starting a new experiment
A new experiment should start on the right-hand side of the notebook (i.e. on an odd-numbered page). If this results in blank pages appearing in your notebook, simply draw a single diagonal line across the blank page(s) to avoid additional data entry; positioning the start of each experiment on an odd page will make it easier for you to locate experiments at a later date.
When recording information into the lab notebook, use a permanent ballpoint pen which has either black or blue ink; this makes it difficult for the records to be erased, in comparison to a pencil or erasable ink. More importantly, when photocopying or scanning the pages of your lab notebook the black or blue ink will offer a good contrast to the white paper.
At the start of any new experiment record the following information:
- The start date (also note date of completion)
- The unique experiment ID (e.g. E.O.III-35)
- A concise summary detailing the “why” (objectives / hypothesis of the study/ chemical reaction)
- References to background literature and/or Standard Operating Procedures (SOPs)
- Materials (including weights, moles, concentration, dilutions, calculations, standards of purity etc)
- Important safety or hazard assessment notes – this can vary significantly from lab to lab so please check your protocols.
Example start to a chemistry-based experiment is shown on the right:
During the experiment
Although it’s quite tempting to perform an experiment and update the lab notebook at a later date, please remember: the purpose of the notebook is to record all elements of the scientific study, from the beginning to the end. So, it’s important that your notes are written continuously and consecutively, whilst in the lab setting. Entries in the lab notebook should be handwritten and legible so that it is clear and easy to read by someone else.
When detailing the experimental procedure, it is commonly written descriptively using full sentences in the past tense and with a passive voice (e.g. “…xyz was added...”).
Therefore, it’s handy to make a note of the following during the experiment:
- Sample preparation
- All observations (detailed description)
- The order of each operation and time taken
- Procedures performed to monitor the progress
The end of the experiment
The “raw” results from the experimental study should be detailed in your lab notebook - this may include a combination of both quantitative and qualitative data.
In the case of a chemical reaction, the results detailed in the lab notebook would include the work up and purification procedures, the yield of the crude and purified isolated product(s), melting point and spectral data obtained.
Alternatively, in the scope of other scientific studies, the results could be in the form of descriptive answers from a study involving patients, or readings from an analytical instrument and even multiple sampling points.
Record the location of stored samples, and any electronic files/folders containing supplementary data, in your lab notebook - this way it will be easier to find later. At the end of the experiment, cross out the white space that remains at the bottom of the final page; that way, no one can go back in and add additional information to the completed experiment.
It may be useful to include some notes detailing possible future work, based on the experimental observations. For example, “the isolated crude compound should be stored under an inert atmosphere and immediately used for the subsequent reaction, due to degradation properties” or “the HPLC column should be flushed with mobile phase B (water/acetonitrile (95:5 v/v)) before analysis”.
Documents related to the experimental study such as spectroscopic data, printed weight sheets, photographs and emails can be attached inside the lab notebook directly after the experimental results - use a staple to attach one corner. If the size or the quantity of inserts is too large, the documents should be stored in a separate folder, with the experiment’s own unique experiment ID on the front cover.
How to deal with common mistakes/disasters
If you need to correct any information never erase or write over text, nor should you ever use correction fluid. Simply draw a single line through the error and add your initials/date to the corrected data. This last point is especially important when working within the requirements of GLP.
Similarly, any attached supplementary data should not be replaced or discarded as this could compromise the integrity of your results. It is also useful to note down a valid reason for the corrections made within the notebook as it allows others to understand the thought processes behind your correction/amendment.
Losing your lab notebook/ supplementary data
The loss of your lab notebook (for example in a lab fire or chemical accident) is possible. This will result in the loss of a significant amount of your data and hard work.
It is therefore good practice to keep back up records of all your experiments, once completed, along with any supplementary data. This could be in the form of electronic files in which the pages of the experiment are scanned and saved electronically in a secure drive.
It’s common for scientists to save a “backup copy” of their electronic files using an external hard drive, which is stored in a secure and fireproof cabinet. When doing so, record the file name and location of the stored file in your notebook e.g. “Casio external hard-drive, in the cabinet in room 410”.
Forgetting key details
When working in a busy lab or conducting an extensive experimental study, it is common to forget to record relevant details into your lab notebook. If this is the case, a recommendation would be to make a note of the missed entry next to the experiment - remember to include your initials and the date of your note entry. To ensure the validity of your experiment and data, it is common to repeat the experiment, and accurately record all procedures and experimental data from the repeated study.
- Kanare HM. Writing the Lab Notebook. Washington DC: American Chemical Society; 1985
- Ebel HF, Bliefert C, Russey WE. The Art of Scientific WritingFrom Student Reports to Professional Publications in Chemistry and Related Fields. 2nd Ed. Weinheim. Wiley-VCH; 2004