FIGURE 2.

HEK cells expressing ΔCR PrP are hypersensitive to G418 (A), Zeocin (B), hygromycin (C), and bleomycin (D). Cells expressing WT or ΔCR PrP or transfected with empty vector were treated with the indicated concentrations of drug for 3 days, and viability was assayed by MTT reduction. Cell viability is expressed as the A₅₇₀ value of treated cells as a percentage of the value for untreated cells. Data points are the mean values of duplicate wells from a single experiment and are representative of at least three similar experiments. Cells in A, B, and D were stably transfected using the expression vector, pcDNA3.1(+) Hygro; cells in C were transiently transfected using the expression vector, pcDNA3.1(+) Neo.