Shelf life (days): 365
Notes: Cayman’s Glutamate Colorimetric/Fluorometric Assay Kit provides both fluorometric and colorimetric methods for measuring glutamate in biological samples such as cell culture media, cell lysates, and tissue homogenates. In the assay, L-glutamate oxidase (LGOX) catalyzes the conversion of glutamate and oxygen (O2) to α-ketoglutarate (α-KG), ammonia (NH3), and hydrogen peroxide (H2O2). In the presence of horseradish peroxidase (HRP), H2O2 reacts stoichiometrically with MaxiProbe to produce a fluorescent compound. The product’s fluorescence can be easily quantified at excitation and emission wavelengths of 530 and 590 nm, respectively. Alternatively, the absorbance of the product can be measured at 570 nm. Background signals generated from H2O2 and other interferences found inherently in samples that are not produced by LGOX in the assay can be corrected by omitting the enzyme in sample background reactions. This assay offers the option to measure fluorescence or absorbance. It is at the user’s discretion to choose the mode of measurement (and corresponding standard curve preparation) that best fits their needs. When read fluorometrically, this assay has a range of 0.3-5 μM and a lower limit of detection (LLOD) of 0.3 μM. When read colorimetrically, the range is 2.6-80 μM, with an LLOD of 2.6 μM.