Rapid serological technique for typing herpes simplex viruses.

A rapid technique is described which can accurately identify a herpes simplex virus (HSV) isolate as type 1 or type 2. Filter paper disks were used to immobilize viral antigens, which were then identified by means of an (125)I-labeled staphylococcal protein A immunoassay. The assay was performed in a specially designed 96-well filtration device which served as both an incubation chamber and a filter manifold. By using this system and cross-absorbed antisera to HSV types 1 and 2, 69 coded clinical isolates of HSV were correctly and unequivocally typed. HSV was also clearly distinguished from varicella-zoster virus and cytomegalovirus. This assay can be rapidly executed (less than 2 h) and yielded an objective endpoint; it required only minute quantities of typing sera and can be easily performed with the cells from a single infected roller tube culture. Thus, it can be used to type initial clinical isolates of HSV, yielding results within hours after the first appearance of cytopathic effects in the culture used for primary virus isolation. Moreover, it is particularly well suited to the simultaneous analysis of many specimens and is amenable to automation. These characteristics suggest that this (125)I-labeled staphylococcal protein A immunofiltration technique will be applicable to the rapid identification of other herpesviruses, as well as other clinical isolates.