Appendix 3
Interpreting Biological Data
I have spent some time discussing molecular techniques, and how and when they are used. A good understanding of these techniques, ie. what sorts of questions do they answer, how do they work and how are the results interpreted, is key to your success in science.
My recommendations for solving biological problems:
1. Read the question very carefully. Mentally perform the experiment.
2. Highlight the important concepts. Do not be misled by superfluous facts.
3. Ensure you know what assay you are looking at. Do not confuse Westerns with gel-shifts, Southerns for Northerns, RT-PCR with S1 nuclease protection, GST pull-downs with chromatin immunoprecipitation etc.
4. What question does the experiment address?
5. Scrutinize every lane in a gel, every band in a lane.
6. Note quantitative and qualitative differences in levels of signal (this goes for gels, Westerns, in situ hybridizations, etc.)
7. Ensure you compare the experimental values with the negative or positive controls.
8. What are the main conclusions?
9. What is the strongest evidence that supports those conclusions?
10. What is the quality of the evidence?
11. Why are the conclusions important?
12. Does your answer completely answer the question? Do not "over-answer" with the idea that the more you write, the greater chance you have of saying something correct.
13. Remember that the answer is right in front of you. It's your job to filter the junk, process the important bits, and convey the interpretation in the simplest way possible.
With these points in mind, please attempt the following problem.