Question

What is not useful as possible DNA probe?

• A. A protein that binds to DNA specifically
• B. A sequence of mRNA that binds to a particular site on the DNA
• C. DNA produced by a DNA synthesizer to have a particular base sequence
• D. cDNA that is complementary to a particular region of the genomic DNA

Answer 1

Answer: (A)

A protein that binds to DNA specifically

DNA probes are used to identify and label DNA fragments that contain a specific sequence. A probe is simply a short length of DNA (20-100 nucleotide length) with a label attached. Probes are used in DNA or RNA sample to detect the presence of nucleotide sequence(the DNA target) that are complementary to the sequence in the probe. DNA probes are used to:

•to identify fragments containing a particular gene out of the thousands of restriction fragments formed from a genomic library.

• to identify short DNA sequences used in DNA fingerprinting.

So, the correct option is 'A protein that binds to DNA specifically'.