CF™350 hydrazide is a highly blue fluorescent dye with a hydrazide reactive group. CF™350 is spectrally similar to the traditional blue fluorescent dye, AMCA. However, compared to AMCA, CF™350 is more water-soluble, more photostable and at least 50% more fluorescent on proteins. CF™350 is at least as bright as Alexa Fluor® 350 and thus can be a direct replacement for the latter for all applications. CF™ dye hydrazides are bright, extremely water-soluble and nontoxic. These properties make the dyes excellent fixable polar tracers for neurons, or for gap junction studies. The dyes can be introduced into cells by microinjection. Hydrazides also can be used for labeling aldehyde or ketone groups, such as carbohydrate molecules after peroxidation with periodate. However, for this application we recommend using CF™ dye aminooxy forms, which are more reactive toward these groups than hydrazide forms.Compatible with the NucleoCounter® NC-3000™.