FIG. 1.

Southern blot analysis of DNA extracted from PBMCs and granulocytes of patient 1, digested with the specified restriction enzymes, and hybridized with the ZVH14 probe. DNA extracted from the HHV-6-infected HSB-2 cell line, infected with the original strain of HHV-6, was used as a positive control. The estimated lengths of the bands obtained are reported in kilobases. The same restriction pattern was obtained for patients 2 and 3 (not shown). No hybridization signal was detected either in the uninfected HSB-2 cell line or in the PBMC and granulocyte samples derived from two HHV-6-negative blood donors (not shown).