Increased detection of herpes simplex virus in MRC-5 cells treated with dimethyl sulfoxide and dexamethasone

Treatment of MRC-5 cells with dexamethasone, dimethyl sulfoxide, or a combination of the two enhanced the detection of herpes simplex virus by three- to fourfold in these cells. Fluorescent plaques were noticeably larger on cover slips treated with the enhancing agents. Low-positive clinical specimens were stored and tested in parallel in treated and untreated shell vials, and 6 to 40% of these stained positive in the treated cultures but not in the untreated controls. In standard tube cultures, cytopathic effect began earlier and was more extensive in treated tubes.