Glutamate is a non-essential amino acid that has a key metabolic role in processes such as the citric acid cycle and removal of excess nitrogen waste. Glutamate has also been identified as one of the major excitatory neurotransmitters of the mammalian brain. Glutamate is involved in learning and memory, and long term potentiation occurs at glutaminergic synapses. In addition, glutamate helps to regulate growth cones and synaptogenesis. Glutamate is also widely used as a flavor enhancer in the food industry.

Glutamate Assay Kit provides a simple, reproducible, and sensitive tool of measuring glutamate concentration in plasma, serum, cell lysates, cell culture supernatants, and other biological liquid samples. This assay employs a coupled enzymatic reaction system that combines multiple steps. Initially, L-glutamate oxidase (LGOX) catalyzes the conversion of glutamate and oxygen to α-ketoglutarate (α-KG), ammonia, and hydrogen peroxide (H2O2). Peroxidase then catalyzes the reaction of hydrogen peroxide with the Colorimetric Probe to form a pink colored product. The optical density measured at 570nm is directly proportional to the concentration of glutamate present in the sample.

• Microplate reader capable of measuring absorbance at 570 nm
• Precision pipettes to deliver 2 μL to 1 mL volumes
• Tubes to prepare sample dilutions
• Incubator at 37°C
• 50 mL conical tubes
• Deionized water

1. Prepare the Reaction Mix (+LGOX), and Background Mix (-LGOX) before use.
2. Add 50 µL of the diluted Glutamate Standards or samples to the 96-well microtiter plate.
3. Initiate the reaction by adding 150 µL Reaction Mix to Glutamate standards and sample wells, 150 µL Background Mix to sample background wells. Carefully shake the plate for a few seconds to mix.
4. Incubate the plate for 40 minutes at 37°C with mixing in the dark.
5. Measure the absorbance at 570 nm using a plate reader.