Keeping a Laboratory Notebook

Purpose: To outline the key features of a lab notebook that will aid in organizing and recording experimental data. The lab notebook should also serve as a tool for planning experiments and developing experimental methods. A good lab notebook can save a lot of time!

Procedure:

1. Obtain a lab notebook number and record the number on the front of your lab notebook. Your lab notebook should be bound and have numbered pages.

2. The first 4-5 pages should be left for a table of contents. The table of contents should list the following information for each experiment: number (e.g. 1, 2, etc), date started, descriptive title, and page numbers.

3. Every entry in the notebook should contain the date, the experiment number, and a title at the top of the page. If you add comments to an entry page on a different date record the new date before commenting.

Experimental Entries:

What to record—what, when, where, why, how, and most importantly, what does it suggest?

1. Enter experiment into table of contents.

2. Purpose: The first time you do a new type of experiment you will need to describe what you plan to do, how you are going to do it, and why. Give relevant information such as the name of the technique employed and any molecules, cell type, etc involved. Subsequent experiments of the same type should note any differences in experimental technique, molecules, cells, etc. and what you hope to learn from the new experiment. You should be able to read the purpose years later and identify quickly how a particular experiment differs from other experiments of the same general kind.

3. Materials: Mostly for chemicals and any non-standard disposable lab supplies used in the experiment. The first time you perform a new type of experiment, make a table with the following information: name, supplier, catalog number, and lot number. Note any chemicals that are stored at temperatures other than room temperature or any special chemical or material handling requirements. Subsequent experiments can reference the page number where the materials are listed, but should note any new materials or new lot numbers used. Keep in mind that materials purchased from suppliers can vary from lot to lot. It may be easier to troubleshoot why something did not work if you have a good record of all variables.

4. Procedure: List the steps involved giving specific details concerning experimental conditions. Note any observations on the effects of a particular step and what the observations might suggest. For established procedures, reference a lab protocol or lab notebook page number and only note any differences in procedure or observed responses. Note the location of any computer data files and the file naming conventions. Fill out an information file and save the information file to the same location. Other forms of data should either be recorded directly into the notebook, glued/taped into the notebook, or have a referenced location such as a labeled paper file, videotapes, CD’s, etc. What data should be recorded will vary widely with the type of experiment so you should come up with a standard way of recording important parameters. A standard table/file format will make comparisons between similar experiments easier. The first time you perform a new type of experiment note the manufacturer and model number of any equipment used. The lab manual contains specific information about each piece of equipment in the lab, so if you know what equipment you used you should be able to reference the manual if further information is required. Include any data analysis such as graphs or calculations at the end of this section. If there is a time lag between data analysis and the start of the next experiment leave a few pages to insert the analysis before recording the next experiment or note the page number where the analysis is inserted.

5. Conclusions: What did you learn from this experiment? Were the results what you expected? Why or why not? Do the results make sense? Can the experimental method/approach be improved or simplified? If so, how? What do you infer from the data and why? What are the possible explanations of an observation or result? Which possibilities are most likely? What are you assuming is happening and how will that change your experimental approach? What would you recommend for future experimental directions? Keeping track of what you think is happening and what assumptions you make can help if you later realize that something else may be happening or offers a better explanation. Always keep in mind what you are trying to learn/achieve from the experiment and whether or not the experimental results provide you with the information you want. How can you modify your approach to get what you want?