TABLE 2.

Comparative analysis of bulk culture and single-cell cloning assays

Cell line and virus	Bulk assay			Single cell cloning			P valueb
	No. of copies of:		% ciHHV-6+	No. of ciHHV-6+ clonesa	Total no. of clones analyzed	% ciHHV-6+
	U65/U66	RPP30
U2OS-HHV-6A	400	43,800	1.8	0	87	0.0	0.4
U2OS-HHV-6B	1,460	44,400	6.6	6	107	5.6	0.8
MCF7-HHV-6A	404	32,000	2.5	2	144	1.4	0.7
MCF7-HHV-6B	386	30,740	2.5	7	143	4.9	0.7

^aFor single-cell cloning analysis, only clones with >0.5 copies of HHV-6/cell were considered positive.

^bP values were determined using chi-square analysis.