BIOLOGICAL DETECTION OF SPECIFIC MESSENGER-RNA MOLECULES BY MICRO-INJECTION

The authors have used direct microinjection of messenger RNA into individual mouse and human cells to assay for specific translation products. They have been able to detect the synthesis of human fibroblast interferon, thymidine kinase, hypoxanthine phosphoribosyltransferase, adenine phosphoribosyltransferase, and propionyl-CoA carboxylase in response to injected mRNA. Using the interferon system as a model, we have quantitated interferon synthesis and followed partial purification of interferon mRNA sequence on sucrose density gradients. The methods they have utilized should be applicable to other systems in which sensitive assays exist for gene products and should provide a screening procedure for isolating specific mRNA sequences.