The Guava ViaCount™ Reagent – 240 mL allows for the quantitative analysis of cell count and viability. The reagent provides precise, accurate assessments on a wide variety of cell lines, even those with unusual culture conditions or a tendency to aggregate. The ViaCount Reagent distinguishes viable and non-viable cells based on differential permeabilities of two DNA-binding dyes in the Guava ViaCount Reagent. The nuclear dye stains only nucleated cells, while the viability dye brightly stains dying cells. This proprietary combination of dyes enables the Guava ViaCount Assay to distinguish viable, apoptotic, and dead cells. Debris is excluded from results based on negative staining with the nuclear dye.