Fixation is not recommended after staining with the Viability/Cytotoxicity Assay Kit (cat. # 30027) as the dead cell dye, EthD-III will transfer to all cells and not maintain dead cell-specific staining. Our Live-or-Dye™ NucFix™ Red (cat. # 32010) is a formaldehyde-fixable dead cell dye that can be used in bacteria.
Viability qPCR (vPCR) can be an alternative strategy for quantitating live and dead bacteria. Using dead cell-specific dyes, PMA (cat. # 40019) or PMAxx (cat. # 40069) that covalently modify DNA (of only dead cells) after photo-crosslinking, a simple quantitative PCR (qPCR) amplification is used to selectively amplify live-cell DNA. Learn more about the vPCR technology.View more FAQs