FIG. 1.

Partial inhibition of MuLV-E transduction by NH₄Cl or BFLA1. Cells were incubated for 30 min in the presence of NH₄Cl or BFLA1 and subsequently infected with a mixture of LAPSN(MuLV-E) and G1nβgSvNa(VSV-G) in medium containing either drug for a period of 2 h. The drug-virus mixture was then replaced by medium containing the drug and incubated for an additional 2 h. The medium containing the drug was then replaced by fresh medium; the culture was allowed to grow to confluence and assayed for transduction by the retroviral vectors as described in Materials and Methods. Percentages of transduction were calculated from the mean values of parallel assays performed in the absence of the drugs. Data for cells treated with NH₄Cl represent the means and SEM of 12 determinations in two separate experiments; data for cells treated by BFLA1 represent the means and SEM of 10 determinations in two separate experiments.