Question

Provide an overview of how gel electrophoresis can be used to analyse genes after

treatment with restriction enzymes or amplification using PCR.

Answer 1

Answer and Explanation:

Agarose gel electrophoresis is generally used to separate the fragments of nucleic acids based on the size.

In case of a gene specific PCR, the PCR product will be loaded to the gel along with the DNA ladder or marker which consists of fragments of known size. In this case, we already know the expected product size of the gene which we want to amplify. So for example, if the expected size of the gene is 1500 bp then we will compare the size of the amplified PCR product with the DNA marker. If the size of the PCR product is approximately the same size as of the expected one then we can confirm that our desired gene is get amplified. If you get multiple bands in that, it means there are some non specific amplifications and may due to problems in annealing temperature.

If the restricted PCR products are loaded in the gel, it should be loaded with the positive and negative controls and also with the ladder. So that by comparing our restricted fragments size to the positive and negative control with the help of DNA ladder we can find out whether the sample is positive or negative for any test.