Effect of centrifugation on herpes simplex virus isolation.

The effects of high-speed centrifugation on the isolation of herpes simplex virus (HSV) were studied. Aliquots of laboratory or clinical specimens were inoculated into test tubes and flat-bottomed tubes containing HEp2 monolayers. Test tubes were incubated at 35 degrees C on roller drums (standard method), and flat-bottomed tubes were centrifuged at 15,000g at 35 degrees C for 1 hr, before being incubated at 35 degrees C without rolling (centrifuged method). Centrifugation of clinical and laboratory specimens of HSV type 1 and HSV type 2 produced significantly increased isolation rates compared with the standard method. When clinical and laboratory specimens were diluted, the centrifuged method was more sensitive at all dilutions. When 20 specimens were used for end-point titrations, the centrifuged method was 10 times more sensitive for 15 specimens and 100 times more sensitive for five specimens. There was no difference in the time taken for the appearance of cytopathic effect (CPE) between the standard and centrifuged methods.