Nalpha-CBZ-L-Citrulline-p-nitroanilide is a fluorogenic substrate for the enzyme nitric oxide synthase. It is used for the detection of nitric oxide in biological fluids and tissue sections, as well as for detecting staining in histological preparations. Nalpha-CBZ-L-Citrulline-p-nitroanilide can be used to detect LPS from Gram negative bacteria, including E. coli and Salmonella typhimurium. This product emits light at 380 nm when it reacts with nitrite ions, which is detected by a luminometer.