TABLE 3.   Inhibition of BPV-1 morphologic transformation of C127 cells by SDS treatment of virus % SDS during treatmenta Final % SDSb No. of foci/platec Expt 1 (day 12) Expt 2  Day 14 Day 17  0 0 266 255 153 5 5 × 103 0 ND ND 5 × 101 5 × 104 0 ND ND 5 × 102 5 × 105 0 0 0 5 × 103 5 × 106 0 271 150 2.5 × 103 2.5 × 106 ND 273 162 5 × 104 5 × 107 ND 229 151 a Sterile SDS stocks (40 times the treatment concentration) were added to virus aliquots to achieve the treatment concentration. b Following virus treatment, treated virus stocks were further diluted 1:1,000 in order to dilute the detergent; the cells in all plates remained viable. c In experiment 1, virus and SDS were mixed and incubated at 37°C for 30 min; in experiment 2, virus and SDS were mixed and incubated at 37°C for 10 min. ND, not done. In control plates without BPV-1, no foci appeared.