SSCP analysis of predominant spectratype bands. Each pair of lanes represents data derived from different samples. Lanes 1 and 2, BV2 from UPN688; lanes 3 and 4, BV20 from UPN855; and lanes 7 and 8, BV5.3 from UPN1074. Lanes 5 and 6 show results from the analysis of a normal, polyclonal spectratype band. In each case, the first lane represents PCR in which twice the amount of cDNA was used.