Spot-blot hybridization assay for the detection of hepatitis B virus DNA in serum: factors determining its sensitivity and specificity.

Factors determining the sensitivity and specificity of the spot-blot hybridization technique for the detection of hepatitis B virus DNA in serum were systematically investigated. Methods for pretreatment of serum samples, mode of application of the samples to the transfer membranes, blot treatment and hybridization conditions were all found to affect the sensitivity of the assay. The optimum hybridization procedure was found to be incubation of serum samples with salt, NaOH, formaldehyde and detergent, followed by spot application of the samples. This method specifically detected hepatitis B virus DNA in serum with a sensitivity 5 to 15 times higher than the presently used assay procedures.