Q. How DNA-RNA hybridization occurs

Both DNA and RNA are able to form hybrids in solution with other RNA or DNA molecules which have complementary base pairing. Double-stranded DNA can be 'denatured' by heating to high temperature. If resulting single-stranded DNAs are slowly cooled, separated DNA strands can reanneal to reform the DNA duplex. Consider that A pairs with T and G pairs with C when a DNA strand hybridizes with another DNA strand. An RNA molecule can also form a base-paired DNA-RNA duplex molecule with a DNA which has complementary base pairing. The most common source of DNA complementary to an mRNA is DNA coding strand that was template for synthesis of the RNA. In DNA-RNA hybrid formation, G base pairs with C, A of the RNA pairs with T of the DNA, and U or RNA pairs with A of the DNA.