Dr. Michael Blaber


Labeling of Samples


Keeping a Lab Notebook



Recently, I have been going through the -80C freezer attempting to consolidate and organize samples from prior students in the lab. This has proven to be an extremely time consuming and frustrating exercise. I have come to the conclusion that I have done a poor job of explaining the correct method of labeling samples, and related to this, the proper way to keep a lab notebook.


The reagents (proteins, plasmids, oligonucleotides, antibodies, etc.) that are produced in our laboratory represent a substantial investment of both time and money. Furthermore, these reagents are a valuable resource, and can assist in speeding up your research projects, and in many cases can save you from having to re-construct, re-express or re-purify various mutants, etc. However, the time and money invested in such reagents, and their ability to help you in your research, are lost if accurate records are not kept.


In going through the samples in the -80C freezer, the majority are inadequately labeled such that it is impossible to know exactly what the sample is, who prepared it, how it was produced, what buffer it is in, what concentration it is, or how old it is. Thus, as reagents, such samples are essentially useless.


The correct labeling of samples must have the following information:


  • Notebook reference number. This will be your initials followed by notebook and page number. For example, "MB3-85" means "Mike Blaber notebook number three, page 85." In those cases where lab personnel have the same initials (e.g. Matt Bernett and Mike Blaber) include your middle initial
  • Sample description (e.g. "FGF L44F")
  • Concentration (mg/ml, absorbance, or molarity)
  • Buffer (typically an acronym reference, where details are to be found in the notebook reference, e.g. "ADA buffer")
  • Date (e.g. 9/10/02)


Here is an appropriate label:



1.12mg/ml 9/10/02


In several cases, the samples in the -80C had ambiguous descriptions (i.e. no buffer listing, no concentration, uncertainty if a kallikrein was active or pro-form, uncertainty if an FGF mutant had a his-tag or not, etc.), and I attempted to go to the student's notebook to clarify these questions. Unfortunately, in many cases the lab notebooks were not helpful in answering these questions.


Here is the format for lab notebooks:


  • The first few pages are reserved for a table of contents. This should be updated as a new entry is written into the book.
  • Dates must be included at the top of each entry.
  • Each notebook entry begins with "PURPOSE", which is a brief statement or two describing the purpose of the experiment.
  • All calculations, notes, materials and methods and descriptions are to be included, with a degree of detail such that someone else reading the notebook, at some point in the future, could be able to repeat the experiment, or understand the exact nature of a labeled sample derived from your research.
  • Results are to be described in appropriate detail.
  • Continuation pages must be indicated at the end of an entry if the experiment or project is continued elsewhere. Similarly, an entry must begin with the referencing page if it continues from a prior date.


Once I finish with the former student's -80C samples, I will be asking each of you to work with me to inventory your samples in the -80C. In this way, the lab will have a useful and accurate inventory of all reagents produced, as well as their location.


The importance of keeping a detailed notebook, and accurately labeling samples, cannot be over-emphasized. It is a professional skill that employers will expect you to be familiar with.




The following page is an entry from my lab notebook as a graduate student (1988). It contains the key items your lab notebook entries should have (date, purpose and sufficient detail to replicate the experiment). Finally, notebook entries should be made in ink.