AnaSpec has developed the OPA protein quantitation kit that employs the OPA reagent for rapid and sensitive protein quantitation in solution. In general, the condensation reaction of OPA with amino-containing compounds requires the coexistence of thiol compound (such as 2-mercaptoethanol) that usually has strong unpleasant odor. AnaSpec’s OPA protein quantitation assay kit uses a proprietary formulation that only contains odorless chemicals. The OPA-based fluorometric protein assay is more sensitive than the absorbance-based methods. The kit functions well in the presence of lipids and detergents, the substances that interfere with many other protein determination methods. AnaSpec’s OPA assay kit has been shown to give faster and more sensitive detection of peptides and proteins. The kit is best used to determine proteins in the range from 3 ug/mL to 250 ug/mL.