Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from GTP by guanylate cyclase and acts as a second messenger much like cyclic AMP. Some hormones, such as acetylcholine, insulin, oxytocin, serotonin, and histamine as well as vasodilators, including niroprusside, nitroglycerin, sodium nitrate, atrial natriuretic peptide (ANP), and nitric oxide (NO) could activate guanylate cyclases and stimulate cGMP levels. Through protein kinases activation, accumulated cGMP can relax smooth muscle and proliferation, phototransduction, and energy homeostasis. cGMP concentration in urine can be measured for kidney function and diabetes detection.

The RayBio^® Cyclic GMP (cGMP) Enzyme Immunoassay (EIA) Kit (EIA-CGMP) is a competitive enzyme immunoassay developed for rapid CGMP detection within 2.5 hours in serum and plasma samples collected from various species including humans, porcine, feline, canine, rabbit, equine and sheep, but not rats or mice. Absorbance is read at 450 nm. The quantity of CGMP is determined by a known standard CGMP curve. The CGMP kit has a high sensitivity of approximately 0.057 pmol/ml. The performance was also verified to exhibit good characteristics in terms of linearity, stability, precision, and spiking & recovery. Each kit provides sufficient reagents to perform up to 96 assays, including standard curve and unknown samples.

• Various species
• High sensitivity
• Rapid detection within 2.5 hours
• Good characteristics in terms of linearity, stability, precision, and spiking & recovery

• Pre-Coated 96-well Strip Microplate
• Assay Diluent
• Lyophilized Standard
• Positive Control
• Capture Antibody
• HRP-conjugated secondary antibody
• Wash Buffer
• TMB One-Step Substrate Reagent
• Stop Solution

• Microplate reader capable of measuring absorbance at 450 nm
• Precision pipettes to deliver 2 μL to 1 mL volumes
• Adjustable 1-25 mL pipettes for reagent preparation
• 100 mL and 1-liter graduated cylinders
• Distilled or deionized water
• Tubes to prepare standard or sample dilutions
• Orbital shaker
• Software which can perform four-parameter logistic regression models

1. Prepare all reagents, samples and standards as instructed.
2. Add 50 µL standards or samples to appropriate well. Incubate for 10 minutes at room temperature.
3. Add 50 µL Capture Antibody to appropriate well. Incubate 1 hour at room temperature or 37°C. And wash 5 times.
4. Add 100 µL prepared HRP-Secondary antibody solution. Incubate 1 hour at room temperature or 37ºC. And wash 5 times.
5. Add 100 µL TMB One-Step Substrate Reagent to each well. Incubate 5-20 minutes at room temperature or 37°C.
6. Add 50 µL Stop Solution to each well. Read at 450 nm immediately.

The entire kit may be stored at -20°C to -80°C for up to 1 year from the date of shipment. For extended storage, it is recommended to store it at -80°C. Avoid repeated freeze-thaw cycles.