Fixable Viability Dyes



Fixable cell viability assays can be used to easily discriminate dead cells from live ones in fixed and unfixed samples in flow cytometry and cell sorting experiments.

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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.

The proprietary cell staining components of VivaFix Fixable Viability Dyes covalently bind to free primary amines: in live cells, these fixable viability dyes bind to the cell surface primary amines. In dead cells, where the membrane is compromised, the dyes permeate the cells and also react with intracellular primary amines (Figure 1). Due to their greater content of accessible free amines, dead cells fluoresce more brightly than live cells, allowing live and dead cell populations to be easily distinguished.


Fig. 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.


Key Benefits of VivaFix Fixable Viability Dyes

  • Cell staining compatible with unfixed cells and post-staining fixation
  • Provides unbiased discrimination between live and dead cell populations — at least 100-fold difference in fluorescence intensity
  • Offered in a wide range of excitation and emission spectra to fit any multicolor experiment

Related Products

These DNA-binding cell staining dyes allow you to assess the viability of your cells:

Additional Products for Flow Cytometry

Bio-Rad also offers reagents and consumables to complete each step of flow cytometry experiments:

  • Cell proliferation assays — easily incorporate 1 of 5 cell proliferation dyes into your multicolor experiment to monitor cell health or cell division
  • Antibody labeling kits — label your antibody of interest in 2 easy steps without a purification column
  • Primary antibodies — use high-quality monoclonal and polyclonal primary antibodies for applications ranging from stem cell, immunology, and cell biology to veterinary research

More Information

Learn more about the features of the S3e Cell Sorter and its associated consumables and accessories.

Both VivaFix Dyes and ReadiLink Antibody Labeling Kits and can be used with the ZOE Fluorescent Cell Imager.




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Pkg of 1, kit includes 4 x 50 assay vials and 250 µl of DMSO, for running 200 assays



Number Description Options
VivaFix™ Cell Viability Assay Product Insert, Rev B
VivaFix™ Cell Viability Assays Flier, Rev B
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