Question

What is the role of biotin in labelling DNA?

Answer 1

Biotin:

1. It is a vitamin, digoxigenin is a steroid from the plant of foxglove.
2. Nucleic acids are readily labeled with tags that facilitate detection or purification.
3. A variety of enzymatic or chemical methods are available to generate nucleic acids labeled with radioactive phosphates, fluorophores, or nucleotides modified with biotin or digoxygenin for example.

Role of biotin in labelling DNA:

1. With the help of these chemicals, scientists can label DNA without any expensive photodetectors or radioactivity.
2. Digoxigenin or biotin are chemically associated with uracil, hence DNA should be synthesized with the labelled uracil substituting thymine.
3. DNA is synthesized in vitro. A single-stranded DNA template, short DNA primer, DNA polymerase and a mix of dGTP, dATP, dCTP plus dUTP associated with either digoxigenin or biotin are combined.
4. Synthesis of the complementary strand to the template occurs by DNA polymerase which incorporates digoxigenin or biotin associated uracil in front of all the adenine.