The Writing Center @ The University of Wisconsin - Madison
The Writer's Handbook
Sample Lab Report

Sample Lab Assignment

Below is a sample lab report assignment from a UW-Madison bacteriology course.

We will be using a format for the lab reports which is similar (but modified) to formats for scientific papers. That is, you must include an abstract, introduction, materials and methods section, results section, discussion, and literature citations. Your grade on the reports will depend on completeness, scientific accuracy and insight, organization, and writing skills. We will discuss this more in lab. We expect lab reports to be prepared using modern word-processing programs.

The format is as follows — point totals for each section are for a 100 point report. For partial or 150 point reports they will be adjusted as needed.


1. Abstract of experiment. (10 points)

This is a summary of the basic content of the experiment. It should state the purpose of the experiment, mention the techniques used, report results obtained, and give conclusions. The point of the abstract is to give a concise summary of the whole report. The most common mistake that students make is not including summary data. Example:

Chromosomal DNA was successfully isolated from Bacillus subtilis strain 151 using a modification of the Marmur technique. Spectrophotometric analysis revealed some contamination with protein, but little RNA contamination. The pure DNA had a concentration of 1.05 mg/ml with a 10.3 mg total yield. The DNA was sterile, as judged by streaking onto penassay agar.


2. Introduction. (20 points)

An introduction gives focus to the report similar to the "Purpose" written in the lab notebook, but also should put the experiment into context and provide the reader with information necessary to understand the scientific basis of the experiment and the techniques used. In most cases, you should include background information on the organisms used and explain the theory behind the techniques. Much of the introductory material should be referenced and references have been put on reserve for you at Steenbock Library. You are encouraged to also search the library for other relevant references.


3. Materials and Methods. (30 points)

This is a section which will be a major deviation from scientific papers. Instead of asking you to tediously rewrite all your lab notes into a materials and methods format, we instead want you to include your lab notes in lieu of materials and methods. The lab notes should be complete, including all raw data, observations, calculations and appropriate graphs.

We do not expect (nor do we want) rewritten notes.


4. Results. (15 points)

Separate from the lab notes, include a section containing a summary of the final data, presented in a form that is most useful for interpreting the results. A short paragraph should be sufficient, along with any relevant charts and graphs labeled well. Remember to title and provide legends for all graphs and tables. The graphs and tables should be comprehenable independently of their association with the text.


5. Discussion. (25 points)

Discuss the experiment and the results obtained. This does not mean you simply report the results again, but rather interpret and discuss their significance. Results should also be compared with those in the literature, if possible. (Be sure to give proper citations). If problems were encountered during the course of the experiment, how might they be rectified in the future? Are there any other things we could do to make this a better experiment or to more specifically address the initial question posed? Are there any better techniques available that would allow one to more accurately generate data? Is there more than one way to explain the results? Your results may support your initial hypothesis, but there may be more than one conclusion that could be drawn from your results. Lastly, do not spend enormous amounts of time explaining data that cannot be explained!


6. Reference Citations

As required in all scientific literature, statements of fact, not considered "common" knowledge, must be properly referenced. Relevant articles for each of our experiments are on reserve in Steenbock Library.

Give complete citations of all literature cited in the report. What's complete? Here are some examples:

Articles in Journals:

Marmur, J. 1961. A procedure for the isolation of deoxyribonucleic acid from

microorganisms. J. Mol. Biol. 3:208-218.

Articles in Books:

Coakley, W.T., A.J. Bates and D. Lloyd. 1977. Disruption of bacterial cells. p279-341. In A.H.

Rose and D.W. Tempest (ed.), Advances in Microbial Physiology, Vol. 16. Academic Press, London and New York.

 

Tim Paustian
Department of Bacteriology
University of Wisconsin-Madison