What is the extinction coefficient of Alexa Fluor 555?

Extinction Coefficient of Alexa Fluor 555

The extinction coefficient is a crucial parameter in fluorescence microscopy and related applications, representing the efficiency with which a dye molecule absorbs light at a specific wavelength. For Alexa Fluor 555, a widely used fluorescent dye in biological imaging and assays, understanding its extinction coefficient is essential for accurate quantitative measurements.

Alexa Fluor 555 is designed to be highly photostable and exhibits a strong absorption peak. The extinction coefficient of Alexa Fluor 555 at its peak absorption wavelength (around 555 nm) is approximately 150,000 M^-1cm^-1. This high value indicates that Alexa Fluor 555 is very efficient at absorbing light, making it an excellent choice for fluorescence-based applications.

The extinction coefficient is vital for determining the concentration of the dye in solution, as it directly influences the fluorescence intensity. By applying the Beer-Lambert law, researchers can quantify the concentration of Alexa Fluor 555 in their samples, enabling precise control over experimental conditions and outcomes.

In summary, the high extinction coefficient of Alexa Fluor 555 makes it a preferred dye for applications requiring high sensitivity and specificity in fluorescence detection.