New one-step cGMP immunoassay with improved sensitivity

When scientists at ArborAssays invented the Direct Cyclic Nucleotide EIA immunoassay more than 20 years ago, they knew the kits would be popular. The direct nature of the format for the assays allows cAMP & cGMP in cells to be measured in one step. They went on to refine the assay, developing both colorimetric and chemiluminescent versions for cAMP and cGMP. But what makes them so popular?

New Cyclic GMP EIA Kit  – enhanced sensitivity with new antibody

Cyclic GMP levels in most systems are an order of magnitude lower than those found for cyclic AMP, hence the constant efforts to develop more reliable and sensitive kits for this target. The new cGMP kit I’d like to introduce in this post is based on a newly developed antibody to provide enhanced sensitivity. This new Cyclic GMP EIA Kit (K065-H) is 2-fold more sensitive than the current cGMP assay (K020-H), as shown in the illustrations below:

cGMP high sensitivity measure in one step EIA kit
The improvement in sensitivity is shown by the Limits of Detection and calculated Sensitivity for the 2 assays, with K065-H being half that of K020-H.

Urine dilutions were run in the nonacetylated format of K065-H and K020-H, side by side, and measured cGMP concentrations were similar. Plasma dilutions were run in the acetylated format for each kit with only a slightly larger difference seen between the measured concentrations.

cGMP high sensitivity measure in one step EIA kit

The DetectX® cGMP Immunoassay kit is designed to quantitatively measure cGMP present in lysed cells, plasma, urine, saliva and culture media samples. The kit is unique in that all samples and standards are diluted into an acidic Sample Diluent which contains special additives and stabilizers designed to lyse cells for measurement. The binding reaction takes 2 hours to complete.  An optional Acetylation Format allows super low concentrations of cGMP to be measured.

Interested in gaining sensitivity in your cGMP measurement? You can indeed with this optimized one-step immunoassay format, just get in touch and I’ll be happy to help!

Main Illustration Credits – Figure: Current concepts of cGMP signalling. cGMP generators (green) and effectors (red), as well as some downstream pathways and cellular functions (grey boxes) that are involved in the effects of endogenous cGMP and/or cGMP-elevating drugs (blue), are shown. The lower part shows some current (blue) as well as potential future (black) indications for drugs that modulate cGMP levels or cGMP effector pathways. BNP, B-type natriuretic peptide; cGKs, cGMP-dependent protein kinases; IRAG, IP3 receptor-associated cGKIβ substrate; PDEs, phosphodiesterases; pGC, particulate guanylyl cyclase; sGC, soluble guanylyl cyclase; VASP, vasodilator-stimulated phosphoprotein. – Robert Feil, Barbara Kemp-Harper, “cGMP signalling: from bench to bedside. Conference on cGMP generators, effectors and therapeutic implications” //

Written by Isabelle Nobiron, PhD
Isabelle is a Product Manager at tebu-bio, and also the company's ISO Quality Manager.