Description; Packaging; 1 kg in poly bottle; 100 g in poly bottle; Biochem/physiol Actions; L-Cystine is a natural proteinogenic amino acid sulfide dimer of L-cysteine. L-cystine is used as a cell culture supplement. L-cystine is also used to characterize and identify specific amino acid transport systems in cells such as system system Xc(─) .; Caution; hygroscopic; handle in <30% humidity