Determination of virus abundance by epifluorescence microscopy

Determination of virus abundance using epifluorescence microscopy is a rapid and accurate method. The protocol requires the concentration of virus particles by collection on a filter. The nucleic acid in the virus particles is then stained with a fluorescent stain and the sample viewed with an epifluorescence microscope. The method was originally developed to determine the abundance of virus particles in water samples, however the protocol has been adapted for cultures and sediment samples. Although the method provides total counts of all virus-sized particles, regardless of infectivity, the method can be used for rapidly screening samples for further study.