APDye Fluor 405(AF405, Alexa Fluor 405 Equivalent) is a blue-fluorescent dye with excitation ideally suited for the 407 nm spectral line of the krypton laser or the 408 nm violet laser diode. APDye Fluor 405 conjugates exhibit an excitation maximum at 401 nm and emission maximum at 421 nm. APDye Fluor 405 conjugates are pH-insensitive from pH 4 to pH 10. It is usually used in multicolor applications, including flow cytometry and super-resolution microscopy using STORM.