Why choose a Cayman Chemical assay kit?

What sets Cayman Chemical kits apart?

The comprehensive collection of immuno- assay kits, cell-based assay kits and enzyme activity assay kits from Cayman Chemical are available in a variety of formats. These kits enable researchers to monitor biomarkers, assess cellular health and measure enzyme activity/inhibition with reliable and reproducible data.

Measure with confidence
Acetylcholinesterase (AChE) is used as the enzymatic label. With the fastest turnover rate of any enzymatic label, AChE assay kits are developed with Ellman's Reagent (containing acetylthiocholine as the substrate). The final product of the enzymatic reaction, 5-thio-2-nitrobenzoic acid, is bright yellow and can be read at 405-420 nm.

Advantages of using AChE over other labels in ELISAs
• Wider dynamic range and greater sensitivity - hydrolysis of acetylthiocholine by AChE shows true first-order kinetics with a turnover of 64,000 sec^-1
• Low background - nonenzymatic hydrolysis of acetylthiocholine in buffer is absent so AChE has a low background and an increased signal/noise ratio compared to TMB
• High sensitivity and precision – average 10 percent CVs
• Completely stable enzyme unlike peroxidase  - plate can be redeveloped if accidently splashed or dropped during development
• Long shelf life - unlike alkaline phosphatase tracers, AChE can be lyophilised allowing tracers prepared with unstable molecules such as LTE4 or LTC4 to be stored for over one year without activity loss
 

Sensitivity defined
Each of Cayman’s assay kits undergoes rigorous quality testing to certify high precision and accuracy to deliver the sensitivity and specificity needed to detect biologically significant analyte levels. Cayman Chemical use an alternative approach to determine the sensitivity of their assay kits.

Competitive ELISA standard curve quantitation
Cayman provides researchers with both the 80 percent B/B0 value and the LLOD along with the assay’s high-low range and 50 percent B/B0 mid-point (the direct centre of the most reliable portion of the curve) to further qualify the ELISA’s robustness. 80 percent binding is the minimum level where reliable, reproducible data can be obtained and represents the minimal functional sensitivity outside of the range of statistical bias.

Competitors typically define by the Lower Limit of Detection (LLOD), usually considered the mean zero plus two standard deviations. While this is the lowest level of analyte detected by the kit, this range is typically not reliable nor reproducible and may reside at a concentration below the linear range of the assay. This value typically lies below an assay’s functional sensitivity range.

A small selection of the Cayman Chemical assay kits available are shown below. To see the full range, search our website or speak to our Cayman Chemical specialists.