Evaluation of 3 nonradioactive DNA detection systems for identification of herpes simplex DNA amplified from cerebrospinal fluid.

The efficiencies of 4 different hybridization assays, using probes labeled with 32P, digoxigenin (DIG) and biotin, were compared for the detection of herpes simplex virus (HSV) DNA amplified from cerebrospinal fluid during herpes simplex encephalitis (HSE). The biotinylated probe was shown to provide a clearly lower sensitivity than the radioactive hybridization system, regardless of whether the biotin-labeled probe was detected by a colorimetric or by a photobiotin assay. In contrast, the DIG system, which includes a luminescent detection step was shown to be equivalent to the 32P system, at least at lower template concentrations. Although generally higher background signals were observed with the DIG assay the analysis of 73 CSF samples yielded identical results with the 32P and the DIG test systems in all cases, identifying concordantly an HSE in 6 patients. Since the time necessary for the performance of both assays is similar the DIG system seems to be a powerful alternative to the radioactive detection of amplified HSV DNA.