Studies on nucleic acid reassociation kinetics: rate of hybridization of excess RNA with DNA, compared to the rate of DNA renaturation.

The rate of reaction of double-stranded replicative form (RF) [3H]DNA of bacteriophage phiX174 with excess (+)strand DNA and (+)strand RNA was measured by standard methods of hydroxyapatite chromatography. The reactions follow pseudo-first-order kinetics and the observed rate constant for the RNA-DNA reaction differs less than 25% from that of the DNA-DNA reaction. The pseudo-first-order rate constants are close to the value predicted on the basis of the second-order rate constant measured in the renaturation of the double-stranded phiX RF [3H]DNA.