Question

Nucleic acid hybridization techniques are based on the observation that?

1) DNA can be very long
2) DNA molecules are very hydrophobic
3) two single stranded nucleic acid molecules of complementary base sequence can form a double stranded hybrid
4) two single stranded nucleic acid molecules of any based sequence can form a double stranded hybrid

Answer 1

Nucleic acid hybridization is based on the ability of complementary single-stranded nucleic acids to form a double-stranded hybrid through hydrogen bonding. Molecules with complementary sticky ends can easily anneal at their sticky ends. Paul Berg was the first to create a recombinant DNA molecule using this technique.

Step-by-step explanation:

Nucleic Acid Hybridization

Nucleic acid hybridization techniques are based on the observation that two single-stranded nucleic acid molecules of complementary base sequence can form a double-stranded hybrid. This phenomenon occurs as a result of the binding between the complementary nitrogenous bases of both strands, facilitated through hydrogen bonding. These bases are adenine with thymine (or uracil in RNA) and cytosine with guanine.

Hybridization involves denaturation, which separates the DNA strands, followed by annealing, allowing the separated strands to re-hybridize. This can occur between DNA molecules or between DNA and RNA. In biotechnological applications, complementary sticky ends of DNA can anneal more efficiently due to the presence of overhanging sequences that form hydrogen bonds. The process is completed by the action of DNA ligase, which ligates or 'glues' the phosphate-sugar backbones to form a stable double-stranded molecule.

Paul Berg utilized this principle in 1972 to create the first recombinant DNA molecule. The stability of the double helix stems from the hydrogen bonds between complementary bases, imparting a double helix structure resembling a spiral staircase to the DNA.