How to Do a Lab Notebook

Adapted from a ComGen handout

Why keep a lab notebook?  
A lab notebook is maintained with the idea that either you (later in time) or someone else must be able
to read and understand what you have done. In addition, notebooks are used settle disputes regarding
who discovered/invented something first. The more readable and complete your notebook is the more
useful it is.

Some General and REALLY IMPORTANT Guidelines

  • Use only a bound notebook with numbered pages (you can number them yourself).
  • Use a pen to write in your notebook and make sure to initial and date every page.
  • Mistakes are not to be erased but should be marked out with a single line.
  • The notebook should always be up‐to‐date.
  • For all experiments, your lab notebook should include not only what you did (materials and methods) but also what you were thinking before you did the experiment, the results of your experiment and the conclusions you reach based on those results and how those results are going to impact your next step.

First pages

  • The inside cover of the notebook should have your full name and signature along with your initials.
  • The first page is a good place to write contact information for lab partners to communicate lab related information.
  • Keep the next few pages of the notebook blank for a table of contents. The table of contents should include the title and pages dedicated to each experiment.
  • Start each new experiment on a new page.

Each experiment should include the following: (* items should be done before coming to lab)

  1. *Title: This should be descriptive but short. For example, the first experiment you list may be “Observation of bean beetle sensory structures”
  2. * Purpose: This will most likely be 1-5 sentences long, depending on the experiment. It should include information on why you are doing this experiment (what’s the main point?).
  3. *Background information: The background section includes information about what is already known about this particular process or experiment. Include any information that is relevant to performing the experiment or interpreting the results. If you are repeating an experiment, clearly state why you are repeating it and what you are changing. This section is likely to include printed or drawn diagrams and references to other sources. Include anything that will be helpful in carrying out the experiment and deciphering the experiment at a later date. If you are using equipment or reagents, this section should include details about what is in each and what each does in detail. Remember, the idea is that you or someone else should be able to repeat the experiment months or years from now using your instructions.  Sources used to obtain information about the lab must be referenced.  I recommend using APA format and NoodleTools Express will help you to make citations.
  4. *Materials and Methods:
    1. Materials
      • Include materials, i.e., solutions or specialized equipment that will be needed
      • Identify your biological samples by genus, species, strain/genotype or any other information that is relevant.
      • Identify enzymes and other reagents by name, vendor, concentration and lot number. (This is very useful for tracking down contaminated reagents and troubleshooting if the experiment doesn’t work as expected.)


      • A protocol (list of steps) must be included that includes every step made. This should be in enough detail that you can use it to troubleshoot errors. For example if 10ul were added rather than 100ul. Times, amounts and speeds should all be indicated. Precision is incredibly important in achieving good results.
  5. Data/Results: Include all raw data, including gel photographs, printouts etc. On gel photographs label all the lanes with letters or numbers and then provide a legend.
  6. Conclusions/Reflections: Write down exactly what you can infer from your data. It is a good idea to “think aloud on paper” as you come to conclusions based on your data. If the experiment didn’t work, write down what went wrong and what will you do the next time to try to make it work. If you cannot make conclusions yet because you don’t have the data, make sure that there are good reflections on what you did.  The results and conclusion sections are extremely important. DO NOT OMIT THESE SECTIONS.

Format of your Lab Notebook:

In industry, laboratory notebooks are legal documents; they are used to determine patent rights, product liability, and accuracy of information. Notebooks should be treated as if they might be used in a court of law at any time because they could be. Occasionally, technicians in biotech companies are fired for not keeping proper notebooks, so the importance of a good notebook cannot be overstated.

NOTEBOOK: a composition book or spiral bound notebook that is used exclusively for lab. Lined or graph paper is your personal preference.

  • On the first pages of your notebook you should include the name of your lab partner(s) and a table of contents (this means pages must be numbered)
  • Lab notebooks are done in PEN only – preferably water proof ink i.e. ball point pen
  • Errors – no white out or scribbles, draw a single line through the error.
  • ALL pages should be numbered in the UPPER OUTSIDE corner of the page
  • The DATE should be written at the very top of each page adjacent to the page number
  • Your SIGNATURE should be included at the bottom of each page
  • A component of your grade is how well you follow these instructions. Following them = free points.
  • Write on the lines – no squishing.
  • Use clear headings for each section – use a separate line for the heading of each section
  • Each week’s lab should start on a new page.

Example Diagram representing 2 pages:

2    1/14/09




1/16/09     3





Multiple Experiments: Sometimes, experiments take more than a single session to

  •  If an experiment is not finished before a second experiment is started, DO NOT leave blank pages to fill in later. Guessing how much room you will need is a bad idea.
  • At the bottom of the page, write: “CONTINUED ON PAGE x”, where “x” is the page number in which your notes will continue for that particular experiment.

Inserts: Taping things into your Notebook

  • Never cover information with anything or store information as a folded sheet. Never fold a page into your notebook. Folded pages make it hard to photocopy material on a complete page.
  • Anything attached to a page in the notebook e.g. graph or protocol that you have printed out; should be neatly trimmed to size and TAPED into the note book with clear tape. All corners of the insert should be taped down. DO NOT glue or staple anything into your notebook.
    • If you tape material into your notebook, write “NWUI” in such a way that it overlaps that edge of that insert and the page to which it is taped; include your initials, and the date. “NWUI” stands for “No Writing Under Insert”.

Notebooks should be kept on the assumption that they may be used for legal verification. In order to do this, it is important to show that you were the one who made changes or taped material into your notebook. Do not worry about your notebook being a work of art (though this is not a bad goal). It is meant to be a permanent record of your work, not a testament to your ability to write notes without any mistakes.

  • ERRORS: Cross out erroneous material by putting a single line through it. Put your initials and the date that the change was made next to the line
    • The use of “Wite‐Out” is not acceptable
  • GAPS: Any gaps in your notebook greater than 4 lines should be marked. Draw a single diagonal line through the blank area, write ILB (Intentionally Left Blank), your initials and date.


  • You should be drawing pictures at a size such that no more than 4 fit on a single page – or larger! i.e. no tiny drawings
  • You may used colored pens or pencils for your drawings, though this is not required.
  • Whenever you draw something that you see on the microscope, you must do the following for EACH picture:
    • indicate total magnification i.e. 40x, 100x, or 400x
    • provide any other details about the set up i.e. commercially prepared slide, wet mount, dimmer setting, setting of the diaphragm and condenser.
    • if you draw a circle to draw in, it is assumed that this represents your “field of view” and hence pictures should be drawn proportionally, i.e. if the specimen fills up the entire field of view, it should also fill up the entire circle that you drew.