The Alexa Fluor 488 cholera toxin subunit B conjugate is labeled with our bright, photostable, green-fluorescent Alexa Fluor 488 dye (which is spectrally similar to fluorescein). The conjugate is derived from nontoxic recombinant B subunit, so it is completely free of the toxic A subunit. Alexa Fluor 488 cholera toxin subunit B conjugate is also available in a unit size of 500 µg (C-22841).