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Viability/Cytotoxicity Assay Kit for Animal Live & Dead Cells

A convenient assay for staining live (green) and dead (red) cells within the same cell population by flow cytometry or fluorescence microscopy

Product Attributes

Apoptosis/viability marker

Live/dead assay

For live or fixed cells

For live/intact cells

Detection method/readout

Fluorescence microscopy, Flow cytometry

Assay type/options

Short term staining (≤24h), Endpoint assay


Green, Red

Catalog #
150 assays
300 assays
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Product Description

The Viability/Cytotoxicity Assay Kit for Animal Live & Dead Cells contains two dyes (calcein AM and EthD-III) for distinguishing live and dead cells.

The assay employs two probes that detect intracellular esterase activity in live cells and compromised plasma membrane integrity in dead cells. The esterase substrate calcein AM stains live cells green, while the membrane-impermeable DNA dye Ethidium homodimer III (EthD-III) stains dead cells red. The kit is suitable for detection using fluorescence microscopy, fluorescence microplate reader, or flow cytometry. The assay principles are general and applicable to most eukaryotic cell types, including adherent cells and certain tissues, but not to bacteria or yeast.

This fluorescence-based method of assessing cell viability can be used in place of trypan blue exclusion, 51Cr release, and similar methods for determining cell viability and cytotoxicity. EthD-III (Cat. #s 40050 & 40051) is a proprietary DNA stain developed by Biotium to be a superior alternative to the spectrally similar dye Ethidium homodimer I (EthD-I). EthD-III has higher DNA binding affinity and thus brighter fluorescence (45% brighter than EthD-I).

Kit Components:

  • Calcein AM, 4 mM in DMSO
  • EthD-III, 2 mM in DMSO/H2O

Spectral Properties (Ex/Em):

  • Calcein (end product after hydrolysis of calcein AM): 494/517 nm (pH 8)
  • Ethidium homodimer III (EthD-III) (with DNA): 522/593 nm (EthD-III also has a large absorption peak at 279 nm)


1. Biotechniques 29, 874-880 (2000).


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