The isomeric mixture of amine-reactive Alexa Fluor 546 carboxylic acid, succinimidyl ester and its conjugates are perfect for applications that require orange-fluorescent probes. Spectrally similar to the Cy3 dye, the Alexa Fluor 546 dye is readily excited by the 546 nm line of the mercury-arc lamp and the 543 nm line of the He-Ne laser. A 5 mg unit size (A-20102) is also available.