The XTT Cell Viability Kit detects formazan dye produced from XTT conversion by mitochondrial enzymes in cells. Because these mitochondrial enzymes are inactivated shortly after cell death, the orange colored formazan dye only appears in viable cells. This XTT Cell Viability Kit is expected to work in most cells lines. Variable with cell type and incubation time employed in the assay, 0.2-2x104 cells/well should be sufficient for most experiments. For the best result, a cell number titration (as shown in Figure 1) is recommended.

The Resazurin Cell Viability Kit detects resorufin produced from resazurin conversion by metabolic enzymes in live cells. This kit is expected to work in most cell lines. For most experiments, 0.02-2x10⁵ cells/well should be sufficient, but this can vary depending on the cell type and incubation time. For best results, a cell number titration and incubation time course (as shown in Figure 1) is recommended. Note: Microbial contaminants will reduce resazurin to resorufin, yielding false positive results. Autofluorescent compounds may interfere with this assay.