TABLE 2.

Frequency of FISH-positive cells in raft cultures harboring wild-type or E4 mutant HPV16 genomes

Genome	Presence of extrachromo- somal viral DNAa	No. of rafts with FISH- positive cells/ all rafts testedf	Frequency of FISH- positive cellsb,e	Relative frequency of FISH-positive cellsc,e
WT	Y	13/14	0.38 ± 0.44	1
16st10	N	(4)/6	0.05 ± 0.05d*	0.05d*
16st15	Y	10/16	0.21 ± 0.34	0.6
16st20	Y	10/10	5.54 ± 4.4*	14*
16st32	Y	5/6	0.62 ± 0.79	1.6
16st67	Y	1/8	<0.01*	<0.01*
16st84	Y	2/8	0.18 ± 0.47*	0.5*
PSS/WT	N	0/3	0*	0*
PSS/20	N	0/3	0*	0*

^aY, extrachromosomal viral DNA was detected; N, extrachromosomal DNA was not detected (see Fig. 2).

^bThe percentage of FISH-positive cells in total number of cells was scored for multiple independently generated rafts harboring the wild-type or E4 mutant HPV16 genomes, as described in Materials and Methods. Raft cultures that do not contain FISH-positive cells were included in the calculation.

^cThe average frequency of FISH-positive cells for wild-type HPV16 populations was set at 1.

^dFrequency of cells containing small punctate signal (see Fig. 6 and Results).

^eAsterisks indicate values for E4 mutant HPV16 genomes that were statistically significant from that of the wild-type HPV16 genome, based on the two-sided Wilcoxon rank sum test.

^fValue in parentheses reflects the number of rafts containing punctate small signal (see arrows in Fig. 6G).