Comparison of reporter molecules for viral in situ hybridization.

A number of streptavidin-linked reporter molecules at the endpoint of a five-step detection protocol for viral in situ hybridization using biotinylated probes were examined. DNA-DNA and RNA-RNA model systems were used. Streptavidin linked to either peroxidase or fluorescein was found to be optimal in terms of sensitivity and resolution within individual cells. All other reporter molecules labelled similar numbers of cells with low background reaction. However, streptavidin-5 nm gold followed by silver enhancement gave very high background staining making interpretation of positive signals very difficult.