Nitric Oxide Synthase Detection System, Fluorimetric

sufficient for 200 reactions

Pricing and availability is not currently available.

Quality Level


sufficient for 200 reactions


not available in Japan

shipped in

wet ice

storage temp.


Gene Information

human ... NOS1(4842), NOS2(4843), NOS2B(201288), NOS2C(645740), NOS3(4846)

Biochem/physiol Actions

Simple and specific assay for the measurement of free nitric oxide (NO) and nitric oxide synthase (NOS) activity in living cells under physiological conditions. Nitric oxide, formed from the amino acid L-arginine via the action of NOS, is a unique cell signaling molecule that functions as both an intracellular and an extracellular messenger. NO has been implicated in vasodilation, neurotransmission, cytotoxicity, and inflammation.
The standard assay for NOS activity is for solubilized cell-free enzyme preparations such as cell lysates, crude tissue extracts or purified enzymes. It measures the production of radio­labeled citrulline from radiolabeled arginine substrate (Sigma Product No. NOS-1). In contrast, the Fluorometric Cell-Associated NOS Detection System measures intracellular production of NO by a non-radiometric method. Radioisotopes are replaced by a cell-permeable diacetate derivative of 4,5-diaminofluorescein (DAF-2 DA). DAF-2 DA penetrates cells rapidly where it is hydrolyzed by intracellular esterase to DAF-2 that, in turn, reacts with NO produced by NOS to form a fluorescent triazolo-fluorescein. The fluorescent product can be quantitated using an excitation filter at 492 nm and an emission filter at 515 nm.

Legal Information

DAF-2 DA is manufactured by Daiichi Pure Chemicals Co., LTD.
US Patent No. 5,874, 590

Kit Components Only

Product No.

  • Diphenyleneiodonium Chloride (DPI) 1 mM 200 μL

  • Arginine Substrate Solution for NOS Detection, Fluorimetric 2 mL

Kit Components Also Available Separately

Product No.

  • D225Diaminofluorescein-2 diacetate (DAF2-DA) 1 mL/vial

  • N9910β-Nicotinamide adenine dinucleotide 2′-phosphate reduced tetrasodium salt, vial of 0.30-0.36 mg 1 vial


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis
Certificate of Origin
Zeming Zhang et al.
Journal of cellular physiology, 234(11), 19715-19727 (2019-04-16)
Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling of the precapillary pulmonary arteries, with excessive proliferation of vascular cells. This study was performed to examine the effects of long noncoding RNA CPS1 intronic transcript 1 (CPS1-IT) on PAH...
D S Bredt et al.
Proceedings of the National Academy of Sciences of the United States of America, 86(22), 9030-9033 (1989-11-01)
Nitric oxide, which mediates influences of numerous neurotransmitters and modulators on vascular smooth muscle and leukocytes, can be formed in the brain from arginine by an enzymatic activity that stoichiometrically generates citrulline. We show that glutamate and related amino acids...
Sabato Sorrentino et al.
Scientific reports, 8(1), 761-761 (2018-01-18)
Peripheral ischemia is associated with higher degree of endothelial dysfunction and a worse prognosis after percutaneous coronary interventions (PCI). However, the role of peripheral ischemia on vascular remodeling in remote districts remains poorly understood. Here we show that the presence of...
H Kojima et al.
Chemical & pharmaceutical bulletin, 46(2), 373-375 (1998-03-21)
Endogenous nitric oxide (NO) appears to modulate many physiological and pathophysiological processes. In order to obtain direct evidence for NO functions in vivo, we have developed 4,5-diaminofluorescein (DAF-2) as a novel fluorescent indicator for NO. Green-fluorescent triazolofluorescein formed by the...
M A Marletta et al.
Current opinion in chemical biology, 2(5), 656-663 (1998-11-18)
The enzyme nitric oxide synthase catalyzes the oxidation of the amino acid L-arginine to L-citrulline and nitric oxide in an NADPH-dependent reaction. Nitric oxide plays a critical role in signal transduction pathways in the cardiovascular and nervous systems and is...

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