Our product Live-Dead Cell Staining Kit is used for simultaneous fluorescence staining of viable and dead cells. This kit contains two dyes-Calcein-AM and Propidium Iodide (PI), which stain viable and dead cells, respectively.

Calcein-AM, acetoxymethyl ester of calcein, is highly lipophilic and cell membrane permeable. Though Calcein-AM itself isn’t a fluorescent molecule, it will turn to Calcein after esterase’s digestion in a viable cell, which could emit strong green fluorescence (excitation: 490 nm, emission: 515 nm). Therefore, Calcein-AM only stains viable cells.

In contrast, PI, a nuclei staining dye, can’t pass through a viable cell membrane. It reaches the nucleus by passing through disorderedareas of dead cell membrane, and intercalates with the DNA double helix of the cell to emit red fluorescence (excitation: 535 nm, emmision: 617 nm).

Since both calcein and PI-DNA can be excited with 490 nm, simultaneous monitoring of viable and dead cells is possible with a fluorescence microscope or flow cytometer. With 545 nm excitation, only dead cells can emit red fluorescence. Since optimal staining conditions constantly changes because of different cell lines, we recommend that a suitable concentration of PI and Calcein-AM should be individually determined.

Please note that PI is suspected to be highly carcinogenic; careful handling is required.

Store at -20°C, protect from light. Calcein-AM is easily hydrolized by moisture. Keep it desiccate and tightly close the cap after the use.