The virion particles pretreated with individual PNA-MTD peptide conjugates at 250 nM (lane 1) and 500 nM (lane 2) concentrations were centrifuged at 100,000 g through a 20% sucrose cushion to separate them from free PNA-MTD peptide conjugates. The scrambled PNA-MTD-peptide conjugate was also used separately as the negative control. The virion pellets were disrupted in disruption buffer. Aliquots of the disrupted virions were examined for endogenous RT activity. The reaction products, after phenol-chloroform extraction and ethanol precipitation, were resolved on 6% denaturing polyacrylamide gel. The control (C) represents the endogenous RT activity in untreated disrupted HIV-1 virions showing products resulting from the strand transfer step. The lane marked M represents the DNA markers corresponding to 90, 250, and 490 bases.