Determination of the frequency of EBV-infected cells in PBMCs by limiting dilution DNA PCR on healthy carrier H3.

(A) Serial dilutions of PBMCs, 8 replicates per input number of PBMCs, were used for DNA isolation. The presence of EBV in the DNA was determined by PCR for the BamH-W region of the virus. The PCR products were analyzed by electrophoresis and Southern hybridization. Lanes 1 to 8 show PCR on replicate samples from the same input number of PBMCs. (B) The percentage of negative BamH-W PCR was plotted against the input number of PBMCs. Curve fitting and Poisson analysis were performed for the estimation of the frequency of EBV-infected cells.