How do you calculate genotype frequency?

particular DNA segment. Geno typing is the process of identifying an individuals genotype and there are a variety of methods for accomplishing this. One of the most common genotype techniques in polymerase chain reaction (PCR), which allows the analysis of very small samples due to its ability to make multiple copies of the DNA fragments.

Difficulty: Moderate

1. 1

   Initialize the sample for polymerases that require a hot start. The sample is typically heated to about 95 degrees Celsius for about 5 minutes. Polymerases that are more thermos table may be heated to greater temperatures.

2. 2

   Denature the DNA fragments. Heat the sample to about 96 degrees Celsius for up to 30 seconds. This will disrupt the hydrogen bonds that join the two halves of the DNA fragment, causing the templates to separate from the primers.

3. 3

   Anneal the DNA templates and primers. Lower the temperature to the 50 to 65 degree Celsius range for about 30 seconds. This will allow hydrogen bonds to form between primers and templates that match each other very closely.

4. 4

   Elongate the primer strands. Raise the temperature to the 75 to 80 degree Celsius range and allow the Taq polymerase to begin synthesizing the primer strands. This can occur at an exponential rate under ideal circumstances.

5. 5

   Repeat steps 2, 3 and 4 approximately 30 times. After the last cycle is completed, a final step holds the sample at about 72 degrees for about 10 minutes to ensure the reaction has completed. The sample can then be stored at about 10 degrees Celsius.