Question

when dna probes are used to identify bacterial dna similarities by hybridization, the probe dna is heated and the template dna is treated to separate the 2 strands. why would the probe dna be heated?

Answer 1

The probe DNA is heated to denature or separate the two strands of the double-stranded DNA to make it single-stranded. This is because hybridization, the process of joining two complementary strands of DNA, can only occur between two single-stranded DNA molecules. By heating the probe DNA, it denatures and becomes single-stranded, allowing it to hybridize with the target DNA under specific conditions. The temperature at which the denaturation or melting occurs depends on the base composition of the DNA, specifically the amount of G-C pairs. This is known as the melting temperature or Tm.