Cell Viability Assays

Fixable Viability Dyes

VivaFix™ Cell Viability Assays enable researchers to accurately discriminate between live and dead cells in unfixed samples by cell staining prior to flow cytometry, cell sorting and microscopy. The live/dead profile is fully preserved in post-staining fixation.

In Flow Cytometry experiments the exclusion of dead cells in a sample is an important step to prevent errors in data interpretation due to non-specific fluorescence signals. In Microscopy cell viability and live:dead cell ratios are parameters that are frequently used to determine cell health.

VivaFix Cell Viability Dyes covalently bind to free primary amines which in live cells are present on the cell surface. Where the membrane is compromised, the dyes permeate the cells and react with intracellular primary amines. There is greater fluorescence due to increased content of accessible free amines in dead cells allowing them to be easily distinguished from live cells (Figure 1). In addition, they are available in a range of excitation and emission spectra for convenient addition to multi-color flow cytometry panels.

Figure 1. VivaFix Cell Viability Assay chemistry. A, live cell with VivaFix Dye bound to surface primary amines. B, dead cell with VivaFix Dye bound to surface and intracellular primary amines.

VivaFix Fixable Viability Dyes Key Benefits

• Cell staining compatible with unfixed cells and post-staining fixation
• Easily distinguish between live and dead cell populations — at least 100-fold difference in fluorescence intensity
• Available in a range of excitation and emission spectra to fit into multi-color panels

Related Products

We also offer non membrane permeable DNA-binding cell staining dyes excited by the 488 nm and 561 nm laser to allow you to assess the viability of your cells:

• 7-AAD Solution
• Propidium Iodide Solution