October 10, 2006
Biology 101 Lab
Polymerase chain reaction, PCR, is a molecular biology technique which takes a
small amount of template, and copies it exponentially. This technique has allowed
scientists to spot mutations, use DNA to identify criminal suspects, as well as sequence
the human genome. DNA samples that were too minute to work with can now be
amplified enough to be experimented on. The template used in this lab was our own
DNA, extracted from our cheek cells. We will use PCR to make copies of the PV92 locus
of chromosome 16, which has two different forms in humans; one contains an extra
repetitive sequence that increases its length. However, whether or not your DNA includes
this Alu element isn’t an indicator of disease or any other known flaw.
The purpose of this experiment was to determine if our DNA contained this extra
Alu element, and whether our genotype was homozygous positive, heterozygous, or
homozygous negative. Another purpose was to learn the importance and various
applications of PCR, and gel electrophoresis.
At the commencement of the experiment, each student began with one cup
containing 10mL of 0.9% saline solution, one screw cap tube containing 200µL of
InstaGene™ matrix, one empty 1.5mL micro test tube, and one empty PCR tube.
First, we labeled all of the tubes and cups that belonged to us, so as not to mix
samples. Next we rinsed the saline solution vigorously in our mouths for 30 seconds, and
dispensed the saline solution, now containing some cheek cells, back into the cup. From
the cup, we poured 1mL of the cheek cell/saline solution into the 1.5mL micro test tube