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What sets our kits apart?
The ACE™ Advantage.
See also: Avidin-Acetylcholinesterase Conjugate
The ACE™ Advantage is the use of acetylcholinesterase
(AChE) as the enzymatic label (US
Patent 5047330) for EIAs. 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 EIAs:
| 1. |
Kinetic Superiority. Hydrolysis of
acetylthiocholine by AChE shows true
first-order kinetics with a turnover of
64,000 sec-1.
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Thus, AChE has a wider dynamic range and
greater sensitivity than other labeling
enzymes.
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| 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.
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| 3. |
High Sensitivity and Precision. AChE assays
offer sensitivity that surpasses most other
immunoassays (both EIA and RIA). Percent
CVs average ≤10.
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| 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.
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| 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).
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