A tetrapeptide derivative (Z-QQIV) to be used as a negative control for ZDON.Formula:C29H44N6O9Molecular Weight:620.7Solubility:DMSO (25mg/ml)Storage and Stability:Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile buffer or dH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.