Application of gene probes to virus detection in water

Gene probes offer a rapid and sensitive method for the detection of viruses in water and other environmental samples. Gene probes are small strands of nucleic acid labeled with radioactive or nonradioactive compounds for their detection. The target organism is identified by the hybridization of the probe oto the organism's nucleic acid. Nucleic acid probes are at least 1000-fold more sensitive than serological tests such as enzyme-linked-immunoassay and do not first require cultivation of the virus for detection. Gene probes have been developed for organisms that do not grow in cell culture, and probes have been constructed for most of the major groups of enteric viruses. Gene probes have been applied to the detection of enteric viruses in water, marine sediment and shellfish. Radioactively labeled probes can detect as little as 1-10 infectious units of virus within 48 hours. A current disadvantage of probes is that they cannot determine the infectivity of the viruses; however, they can be used to quickly determine the growth of viruses in cell culture. Further development of nonradioactive probes should place virus detection capabilities into the hands of most water quality laboratories.