& Data Analysis
Protein gel analysis
Keeping a lab notebook
Writing research papers
Dimensions & units
Using figures (graphs)
Examples of graphs
Principles of microscopy
Solutions & dilutions
Fractionation & centrifugation
Radioisotopes and detection
Guide to the study
Lab part 1
Lab part 2
Flagella Regeneration – Data Collection
Sampling at timed intervals will enable us to record the progress of regrowth of flagella. Cultures can be maintained under identical conditions and small representative samples removed for measurement, leaving the rest of the culture to continue. Samples must be fixed and stained to preserve the structures as they were at the exact moment of sampling, and to enable visualization of flagella.
A complete data set of data should include measurements taken at approximately ten minute invervals at the beginning of the experiment, perhaps with wider intervals (e.g., 15 minutes) toward the end if rates of change appear to be slowing. For non-deflagellated samples it should be sufficient to record average flagella length at the beginning and again at the end of the experiment.
A team of four people sharing two microscopes should have little or no trouble collecting data for this study. Here is how we will set up the experiment for a class of 20 or so.
We will use Lugol's iodine for fixing the samples. If the colchicine treated samples rupture, then double the ratio of culture to iodine solution for those samples only.
Recommended scoring intervals
To obtain a time course for regeneration (if regeneration takes place), try to sample the untreated deflagellated culture and the experimental culture (deflagellated and treated with 10 µg/ml cycloheximide) at 10 minute intervals. The colchicine treated deflagellated culture is not expected to regenerate flagella, so we don't need to sample as often. One sample at the start, one in the middle of the experiment, and one at the end should be enough.
Non-deflagellated cultures should be examined at the start of the experiment and at the end, at minimum. If you have time, check each of them once or twice during the experiment itself. We are only interested in whether or not there is a significant change in average flagella length over the time course of the study.
Analyzing the data
You'll be evaluated in part on your success as a team in collecting a usable set of data. Others may need your data, so be prepared to share. Details related to data analysis are presented in the talk on quantitative methods.