Method of Analysis:Flow Cytometry, Fluorescence Microscope
Intended Use:Advanced Calcein AM Cell Viability BioAssay™ Kit combines Calcein AM with 7-AAD to allow for easy and simultaneous labeling of live, membrane compromised, and dead cells within a single sample. Calcein AM is used to detect live cells, fluorescing green, while 7-AAD is used to detect necrotic or late stage apoptotic cells, fluorescing red. Samples can be analyzed using a flow cytometry or fluorescent microscope.
Test Principle:Assessment of cell viability is a critical step during the evaluation of novel drug treatments and therapies for potential cytotoxic properties. Advanced Calcein AM Cell Viability BioAssay™ Kit combines Calcein AM with 7-AAD to allow for easy and simultaneous labeling of live, membrane compromised, and dead cells within a single sample.
Calcein AM is a membrane permeant, fluorogenic, reagent widely recognized for its utility in assessing the relative cell viability status of different cell populations. Calcein AM’s overall hydrophobic nature allows it to readily traverse the lipid bilayer structure of the cell membrane in a concentration gradient-dependent manner. Once inside the cell, the hydrophobic and non-fluorescent Calcein AM is quickly hydrolyzed by intracellular esterases that are active in live cells. This leads to the cleavage and removal of two non-polar acetoxymethyl ester (AM) groups. Once the AM groups have been cleaved, the resulting polar (hydrophilic) and now fluorescence-capable Calcein dye molecule is efficiently retained within the confines of the cell membrane. Polar dye molecules will naturally be excluded from passive diffusion back out of the cell again due to the hydrophobic lipid bilayer composition of the cell membrane. Dead cells lack active esterases and do not cleave Calcein AM.
Loss of cell membrane integrity, often indicative of necrosis or late stage apoptosis, can be detected using the vital staining dye, 7-AAD, a red fluorescing live/dead stain. This dye easily penetrates cell membrane-compromised cells, binding tightly to GC rich regions of DNA. Combining these two different types of fluorescent cell-status-indicator reagents within a single test allows for better resolution of the live and dead cell populations by making it possible to identify the percentage of cells that are 7-AAD positive versus 7-AAD negative within the green fluorescing Calcein positive cell populations.
Samples can be analyzed using a flow cytometer or fluorescent microscope.
Storage and Stability:Store powder at 4°C liquid at -20°C. Store other components at 4°C. Stable for 6 months For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
