Friday, September 19, 2008

LABS 3 and 4 - RED and PV92 PCR Gel electrophoreses

Today we finished labs 3 and 4, which we started yesterday.

Lab 3 - Restriction Enzyme Digestions - Gel electrophoresis

We loaded the DNA digestions that we set up yesterday, plus a standard (a.k.a. marker or ladder). Once again, the DNA that was digested (and an un-digested control) came from the lambda bacteriophage, a common phage of E. coli. The enzymes used for the digestion were HindIII, PstI, and EcoRI. The marker was a precut lambda bacteriophage DNA, HindIII.

Methods and results at this point should resemble the ones from lab 2. You need to do a visual estiumation of size of DNA bands, and then use the precut HindIII digestion bands to create a migration distance vs. band size curve in semi-log paper and interpolate (and extrapolate) the information obtained from other samples.

Nice thing about this lab is that STUDENTS actually estimated the band migration distance, as opposed to last week, when the instrctor did it.

Lab 4 - PV92 PCR - Gel electrophoresis

Yesterday after lab, the instructor added the PCR master mix to the human DNA samples donated by the students, and put all the tubes in the thremocycler to perform a PCR to amplify the PV92 locus. Today students ran gel electrphoreses to vizualize the results and determine if they are homozygous (positive or negative) for the Alu sequence insertion in the PV92 DNA segment.

Results will be used to perform a quick and basic bioinformatics exercise using the obtained information in the Allele Server webpage. Access the Dolan DNA Learning Center Gene Almanac and click on 'Resources', then on 'Bioservers' and log on to 'Allele Server'. The username is a-cordoba, and the password is biol217.

Once in there click on 'add data'. On the pull-down menu 'please choose your group' click on 'ONU-biol 217' (which should be the default). The password is biol217 and your number is the one I assigned to you on an e-mail that I sent.
Enter the information (you don't have to enter info about your parents' descent if you don't want to) and click ok. Once all of us have done that we can play with the data and find out a few things of us as a "population".

To VIEW the information, click on 'Manage Groups', and click on 'View' in front of the 'ONU-Biol 217' group.

Click here to find more information about PV92 and the Alu sequence!

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