iE-Lys iE-DAP negative control γ-D-Glu-Lys (iE-Lys) is a dipeptide present in the peptidoglycan (PGN) of Gram-positive bacteria. iE-Lys is not recognized by NOD1 (CARD4), in contrast to iE-DAP which is found mainly in Gram-negative bacteria. Thus iE-Lys can be used as a negative control for NOD1 activation studies with iE-DAP or its derivative C12-iE-DAP. Working Concentration: 1 - 100 µg/ml Endotoxin level: <0.125 EU/ml Solubility: 10 mg/ml in water Synonym: γ-D-glutamyl-Lysine Formula: C11H21N3O5 Molecular weight: 275.30