RNA-RNA hybridization between influenza viruses.

A study is described of the RNAs of recombinant viruses made from A/PR/8/34, which is non-infectious for man, and wild human Influenza A strains. By RNA-RNA hybridization it was possible to determine the proportion of the genome donated by each of the parents. The technique can be applied as a biochemical marker to detect the recombinants among parental viruses and moreover, it is a method to select the attenuated viruses among the recombinants.