A policeman finds a very small piece of body tissue from the site of a crime and takes it to the forensic department.
a. By which technique will they amplify the DNA collected from the tissue sample?
b. Mention in a sequence, the three steps involved in each cycle of this technique.
c. What is the role of thermostable DNA polymerase in this technique?

Explanation

a. DNA fingerprinting is very useful technique to identify criminals in the forensic laboratories.
b. i. DNA is cut into fragments with restriction enzymes into precise reproducible sequence.
ii. Separated DNA sequence are transformed on to a nitro cellulose or nylon membrane.
iii. This sequence probes target a specific nucleotide sequence that is complementary to them.
c. DNA is extracted from the cells in a high speed refrigerated centrifuge and many copies of the extracted DNA are made by polymerase chain reaction.