Lab Notebooks

Lab Notebooks & Record Keeping:

As you move from labs with pre-defined protocols into research (where you have to define your own protocol), your lab notebook becomes increasingly important as both a place to plan out your work and where you keep an accurate and complete record of what you’ve done. When you are designing your own experiments, careful planning ahead of time ensures that your time in lab is well spent and productive and minimizes both potential safety hazards and waste of materials. That said, research is inherently pushing the boundaries of knowledge. As such, planning will only take a project so far results are frequently not something that you can exactly predict when you’re working with new systems. Moreover, some of the most interesting results are those which we didn’t anticipate and can lead to discovery.

Keeping an accurate record of your results is what lets you go back and figure out what happened when a result is unexpected. Details that may not have seemed important at the time can be what explains why two seemingly similar experiments can lead to different results. Additionally, as scientists we frequently have to refer back months (or even years) to compare new data against old data, as well as to refer to protocols to write up our results. As such, your lab notebook should be updated constantly during lab to ensure that you are writing down exactly what you’re doing- sometimes it may vary slightly from what you planned on doing, and that difference may be key later. As a general rule, write everything down. If you aren’t sure whether a detail should be recorded or not, you should err on the side of writing it down! You may not need it in the future, but if you do you will be very glad you have it. Similarly, every entry should have a date and every page should be numbered.

A complete notebook entry for an experiment contains three general sections of information: things done before starting the experiment, things done during the experiment, and things done after the experiment. More specifically, the following sections are frequently used:

1. Introduction, Protocol, Background & References (Before Starting)

• Before you begin working, you need to lay out what you’re planning to do and any necessary background information. This should include:

  • • • title of the experiment and brief description of your goal(s)

      • protocols or procedures you are planning to follow or details of the experiments you’ve designed.

      • a section (as needed) detailing hazards and properties of any new chemicals or compounds you’re working with.

      • if you’re basing your work off something in the literature, you should reference it.

2. Data & Observations (In Lab)

• As you perform an experiment, you will have major and minor deviations from the planned procedure/protocol. Each of these should be clearly noted in your lab notebook. All exact amounts of reagents used, any measurements taken, and/or changes to reagent types or formulations should be noted specifically.

• Some of the most important data in a lab is qualitative: note your observations and thoughts as you progress through an experiment. Things that don't look right, questions you have, and any other things you notice can be extremely helpful troubleshooting a project down the road.

3. Calculations and Data Analysis

• A good lab notebook does not stop with experimental data. Consistent calculations and data analysis are just as important to your final conclusions, and the methods and values you use should be noted in your lab notebook, along with a brief description of any analytical methods you employed (i.e., data fitting methods or equations)

• Additionally, it’s often a good idea to keep physical copies of data generated (plots, graphs, pictures of gels, etc.) in your notebook along with the experiment to refer back to.

4. Discussion and Conclusions

• After you have finished your data analysis, you should take the time to write brief points of discussion and conclusions. These can draw attention to observations that may explain aberrant data or may point out new directions that could shed light on a question that came up while you were working. 

In addition to keeping good records in your lab notebook, you should make sure that you are consistent in storing and organizing digital data: files should be saved consistently (year_mo_da_experiment_name), and the file name should always be recorded in your lab notebook so you (or someone else) can find it. 

Your lab notebook isn’t just a record for you to follow, but is also a record that is critical to data reproducibility and eventual ability to publish data you contributed to in the lab. Make sure you organize your notebooks so they are easily followed by someone else reading through them,  especially by making sure you keep an updated and accurate table of contents.