Calcein AM is a membrane-permeable live cell labeling dye. Upon entry into cells, intracellular esterases cleave the ester group of acetoxymethyl (AM), producing a membrane-impermeable calcein fluorescent dye. The cell membranes of apoptotic and dead cells have been damaged and cannot retain calcein. The optimal excitation wavelength of calcein is 495 nm, and the emission peak is 515 nm. For fluorescence microscopy, calcein can be detected using an appropriate filter set. For flow cytometric analysis, excitation is performed with a blue laser line (488 nm) and detection is performed using a filter suitable for FITC/Alexa Fluor™ 488 (530/30). For multicolor flow cytometric analysis, the recommended concentration range is 5 – 20 nM to ensure successful compensation. Co-staining with Annexin V or 7-AAD is recommended to better differentiate between live and dead/apoptotic cells. If single-color analysis is required, use Calcein Blue AM (Cat. No. 65-0855) or Calcein Violet 450 AM (Cat. No. 65-0854) to better differentiate between live and dead/apoptotic cells.

Molecular weight: 994.86
Excitation peak: 495 nm
Emission peak: 515 nm

Newly opened high-quality DMSO should be used to reconstitute Calcein AM.
After reconstitution, it should be stored with desiccant at -20°C and used within a short period of time. Avoid freezing and thawing.

Purity
> 95% (HPLC method)

Reported Applications
Flow cytometry analysis, Microscopy