L-Arginine (Arg) is a proteogenic, semi-essential amino acid: healthy humans can synthesize L-Arginine using L-Glutamine as a building block. However, premature infants are unable to produce Arg and additional supplementation is required for proper growth and development. Arginine plays pivotal roles in biochemical pathways such as the urea cycle and the biosynthesis of nitric oxide. Arginine and Ammonia concentrations are elevated in patients having a mutation in their ARG1 genes. The mutation causes lower arginase activities – a condition that is known as Argininemia. Arginine has also been advertised as a supplement due to its role in the synthesis of nitric oxide, which helps in vasodilation processes. BioVision’s L-Arginine Assay Kit provides a quick, specific, and easy method for the measurement of total L-arginine concentrations in a wide variety of samples. In our enzyme-based assay, L-arginine is converted into a series of intermediates, which will further react with a probe producing a stable fluorescence signal (Ex/Em = 535/587 nm). The kit is simple to perform, specific, high-throughput adaptable and sensitive– it can detect as low as 100 pmol/well of L-arginine in human biofluids and other biological samples.