Excluding dead cells from data is recommended for all staining protocols to ensure experimental accuracy. VIV-ON fixable viability dyes allow accurate discrimination between live and dead cells in flow cytometry analysis, based on cell membrane integrity. VIV-ON preserve the staining pattern after fixation and/or permeabilization.

VIV-ON fixable viability dyes are amine reactive and cell impermeable. Dead cells with compromised cell membranes are typically labelled to a higher extend due to reaction with intracellular amines resulting in highly fluorescent dead cells. Impermeable live cells, on the contrary, are labelled only on the cell surface and show dim fluorescence