News from the Bench

Discover what’s going on at CST, receive our latest application notes and tips, read our science features, and learn about our products.

Subscribe

Our U.S. Offices Will Be Closing Early

Our U.S. offices will be closing early on November 26th at 6:00 PM EST.

To Purchase # 4360S

4360S 1 Kit (96 assays)

To get local purchase information on this product, click here

Questions?

Find answers on our FAQs page.

ANSWERS  

Visit PhosphoSitePlus®

PTM information and tools available.

LEARN MORE

Product Includes Quantity (with Count) Solution Color
cGMP Ab Coated Microwells 96 assays
cGMP-HRP Conjugate 11 ml Red
cGMP Standard 1 ml Colorless
TMB Substrate 7004 11 ml Colorless
STOP Solution 7002 11 ml Colorless
Sealing Tape 2 sheets
ELISA Wash Buffer (20X) 10 ml Colorless
Cell Lysis Buffer (10X) 9803 15 ml Yellowish

Product Description

The Cyclic GMP XP® Assay Kit is a competition enzyme-linked immunoassay used to determine cGMP levels in cells or tissues of interest. In this assay, cGMP found in test sample competes with a fixed amount of HRP-linked cGMP for binding to an anti-cGMP XP® Rabbit mAb immobilized onto a 96-well plate. Following washing to remove excess sample cGMP and HRP-linked cGMP, HRP substrate TMB is added to develop color. Because of the competitive nature of this assay, the magnitude of the absorbance for this developed color is inversely proportional to the quantity of sample cGMP. Measurement of absorbance using the cGMP Standard allows calculating the absolute amount of cGMP in a sample of interest.

Note: 12 8-well modules - Each module is designed to break apart for 8 tests.


Specificity / Sensitivity

The immunoreactivity of this kit was tested against the following: ADP, AMP, ATP, cAMP, cGMP, cIMP, cTMP, CTP, GDP, GMP and GTP. Minor cross-reactivity was observed with cIMP, with over 100 fold higher sensitivity for cGMP compared to cIMP. No cross-reactivity was observed with any of the other factors tested. Kit sensitivity, as shown in Figure 1, demonstrates a dynamic range of 2 to 200 nM of cGMP. Changes in cellular cGMP levels following specific treatments are shown in Figure 2 and Figure 3 (low passage RFL-6 cells).


Cyclic guanosine 3’,5’-monophosphate (cGMP) is a critical and multifunctional second messenger molecule involved in many signal transduction pathways in different cell types of almost all species (1). Intracellular cGMP is generated from GTP by guanylyl cyclase (GC) and degraded through phosphodiesterase (PDE) hydrolysis (1,2). Two distinctive families of GC have been identified: soluble guanylyl cyclases (sGC) that are nitric oxide-responsive and cell membrane-bound, particulate guanylyl cyclases (pGC) that respond to diverse extracellular agonists including peptide hormones, bacterial toxins and free radicals (2,3). Phosphodiesterases form a superfamily of 11 isoforms with different specificity to both cyclic adenosine 3’,5’-monophosphate (cAMP) and cGMP (4). Cyclic GMP regulates cellular physiology by activating cGMP-dependent kinase, modulating cGMP-dependent ion channels or transporters, and altering its own hydrolytic degradation by phosphodiesterase (PDE) (1,4). Because of the diversity of its effectors, cGMP plays an important role in regulating various pathological and physiological processes, such as vascular smooth muscle motility, intestinal fluid and electrolyte homeostasis, and retinal phototransduction (1,5).


1.  Domek-Łopacińska, K. and Strosznajder, J.B. (2005) J Physiol Pharmacol 56 Suppl 2, 15-34.

2.  Lucas, K.A. et al. (2000) Pharmacol Rev 52, 375-414.

3.  Potter, L.R. et al. (2006) Endocr Rev 27, 47-72.

4.  Matsumoto, T. et al. (2003) J Smooth Muscle Res 39, 67-86.

5.  Rybalkin, S.D. et al. (2003) Circ Res 93, 280-91.



For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology® is a trademark of Cell Signaling Technology, Inc.
XP® is a trademark of Cell Signaling Technology, Inc.