Question

Explain the steps of DNA fingerprinting that will help in processing of the two blood samples R and S picked up from the crime scene.

Answer 1

The following crucial procedures are used in DNA fingerprinting to match or identify people by comparing DNA samples, such as blood samples R and S from a crime scene.

1. Collection of DNA: Blood samples R and S are taken from a suspect, the crime scene, or another pertinent source.
2. Extraction of DNA: Chemical solutions that break cell membranes are used to extract the DNA from the cells in the blood samples.
3. Cutting DNA with Restriction Enzymes: Restriction enzymes, which function as molecular scissors to cut DNA at particular sequences and produce pieces of varying lengths, are applied to the extracted DNA.
4. Gel Electrophoresis: Through the use of an electric field, which causes smaller fragments to flow through the gel more quickly and larger fragments to move more slowly, the DNA fragments are separated according to size using gel electrophoresis.
5. Transfer and Hybridisation: Southern blotting is the technique of transferring the isolated DNA fragments to a membrane. The precise DNA segments of interest are bound by probes, which are short DNA sequences complementary to the repetitive portions of the DNA.
6. Analysis of Banding Patterns: The DNA band pattern created by the probes is seen and contrasted. Analysis is done on the distinct band pattern (DNA fingerprint) from samples R and S. The samples may be from the same person if the banding patterns match. They originate from various people if they are different.