The kinetics of in situ hybridization.

The kinetics of the cytological or in situ DNA-RNA hybridization reaction between 125-I HeLa cell 18S and 28S rRNA and the interphase nuclei of chinese hamster cells were studied. The reaction is consistent with the expected first order kinetics, and the value of the rate constant was very similar to the value obtained from analogous filter disc DNA-RNA hybridization experiments. This similarity in the rate constants and the known relationship between the rate constant and the complexity of the RNA hybridized, define conditions to optimize the in situ hybridization reaction.