Effect of hemin on DRAW and RAW cells. Cells, seeded at a density of 2.5 × 104 cells/well in 96-well plates, were treated with 65 μg/ml hemin or untreated. (A) Virus yield from DRAW cells was measured in function of time by plaque assay in L929 cells. Data are the mean result of duplicate samples from two independent experiments ± standard deviation; * P < 0.05 (unpaired Student's t test between untreated and compound-treated samples). (B) Cell viability of hemin-treated cells was assayed using Promega's CellTiter-Blue kit on triplicate samples and expressed as a percentage of the values from untreated control cells ± standard deviation; * P < 0.05 (unpaired Student's t test between hemin-treated RAW and DRAW cells. Phase-contrast images of (C) hemin-induced lysis of DRAW cells and (D) normal appearing hemin-treated RAW cells. Magnification: 400×.