Question

What does DNA fingerprinting involve?

Answer 1

DNA fingerprinting:

1. DNA fingerprinting is a technique for assessing a person's potential identity by determining variations in nucleotide sequences.
2. This process is usually performed by matching human-specific nucleotide sequences.
3. The DNA fingerprint contains a series of powerful and important steps to complete and develop the DNA fingerprint of a father, suspect, or individual involved in immigration issues.
4. The DNA fingerprinting process begins with the separation of DNA from every part of the body, including blood, semen, vaginal fluid, hair roots, teeth, and bones.

DNA fingerprinting involves:

Isolation of DNA:

1. The polymerase chain reaction (PCR) is the next step in this process.
2. In many cases, very little DNA can be used for DNA fingerprinting.
3. For this reason, DNA replication must be done in vitro to produce more DNA.
4. DNA and cells undergo DNA replication to produce more DNA to be tested.

Restriction enzyme:

1. The DNA is tested after it has been separated and a further copy of the DNA has been made.
2. Scientists process DNA with restriction enzymes, enzymes that cut DNA near specific recognition nucleotide sequences known as restriction sites.
3. This creates fragments of various sizes called restriction enzyme fragment length polymorphisms (RFLPs).

Electrophoresis:

1. These fragments can be observed in an experiment called gel electrophoresis that separates DNA based on fragment size.
2. Gel electrophoresis is the next step in this DNA fingerprinting process.
3. In-gel electrophoresis, an electric current is passed through a gel mixture containing a sample of DNA.
4. The electric current moves the DNA strands through the gel.
5. This separates molecules of various sizes.

Interpretation of bands patterns:

1. The separated pieces of DNA are sifted from the gel using a nylon membrane (treated with a single-stranded chemical that breaks the hydrogen bonds in the DNA).
2. DNA is crosslinked to nylon using heat or ultraviolet light.
3. The probe appears on photographic film as the DNA strands break down and emit light.
4. It leaves a dark spot on the film, also known as the human DNA band.
5. It is the unique pattern of the band that makes up the fingerprint.
6. Ribbon patterns are different because we are all different and unique (except for the same twins).
7. When the filter is exposed to x-ray film, the radioactive DNA sequence becomes visible and visible to the naked eye.
8. This creates a striped pattern.
9. This technique is called Southern blotting.