Effect of D18 and quinacrine treatments on PrPSc levels in ScGT1 cells. RML infected GT1 were treated for 6 days with 1 μM quinacrine and 50 nM D18. Cell lysates were digested with proteinase K (PK, PK+ lanes) as described in Materials and Methods and PrPSc content was detected by Western blot. Twenty μg of total proteins (PK-lanes) were loaded as control. Noticeably, PK-resistant PrP was completely cleared in GT1 cells.