X-press Tag is an N-terminal leader peptide; this N-terminal peptide contains a polyhistidine sequence, the Xpress epitope (part of bacteriophage T7 gene 10 protein) and an enterokinase cleavage site. Anti-Xpress antibodies recognize the Xpress epitope sequence found in this leader peptide.

IDE1 can induce definitive endoderm from embryonic stem cells. It has been shown to induce the differentiation of Sox17+/FoxA2+-expressing pancreatic progenitors from human and mouse embryonic stems cells.

DL-Carnitine HCl is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine.