The ACE™ Advantage | Cayman Chemical

What sets our kits apart?

Our kits use acetylcholinesterase (AChE) as the enzymatic label. AChE has the fastest turnover rate of any enzymatic label. AChE assays are developed with Ellman's Reagent, which contains 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.

AChE offers several advantages over other enzymes conventionally used in ELISAs:

  1. Kinetic Superiority. Hydrolysis of acetylthiocholine by AChE shows true first-order kinetics with a turnover of 64,000 sec-1. Thus, AChE has a wider dynamic range and greater sensitivity than other labeling enzymes.
  2. Low Background. Non-enzymatic hydrolysis of acetylthiocholine in buffer is essentially absent. Consequently, AChE has a low background and an increased signal/noise ratio as compared to TMB (a peroxidase substrate) which is inherently unstable.
  3. High Sensitivity and Precision. AChE assays offer sensitivity that surpasses most other immunoassays (both ELISA and RIA). Percent CVs average ≤10.
  4. Versatility. AChE is a completely stable enzyme, unlike peroxidase which is suicidal. Thus, if an AChE plate is accidentally splashed or dropped during development, it can be re-developed by washing the plate and adding fresh Ellman's Reagent.
  5. Shelf Life. Unlike Alkaline Phosphatase (AP) tracers, AChE can be lyophilized allowing tracers prepared with unstable molecules such as LTE4 or LTC4 to be stored for more than a year without loss of activity. For stable analytes, such as 8-isoprostane, AChE tracers are remarkably stable in solution for prolonged periods of time even at room temperature (see Figure below).

Stability of 8-isoprostane tracer

Cayman Chemical

1180 East Ellsworth Road

Ann Arbor, Michigan 48108 USA

Toll Free: (800) 364-9897

(USA and Canada Only)

Fax: (734) 971-3640