Caution Do not freeze. General description Low salt Reconstitution When reconstituted in 0.25 mL distilled water, the compound contains 500 μg of protein in 0.01 M sodium phosphate at pH 7.5. Biochem/physiol Actions The cholera toxin B subunit is used for track tracing in neurological research, taking advantage of GM1 ganglioside binding and retrograde transport. Tissue culture cells treated with cholera toxin are not killed and tissues of animals do not become necrotic.