The Amplex™ Red Acetylcholine/Acetylcholinesterase Assay Kit provides an ultrasensitive method for detecting acetylcholinesterase (AChE) activity in a fluorescence microplate reader or fluorometer.

See our complete line of Fluorescence Microplate assays.

• Detect AChE activity levels as low as 0.002 U/mL in one hour
• Detect acetylcholine levels as low as 0.3 μM using excess AChE
• Achieve detection ranges of 0.3 μM to 100 μM acetylcholine
• Format allows for multiple time point measurements
• Designed for minimal autofluorescence interference

AChE activity is monitored indirectly using 10-acetyl-3,7-dihydroxyphenoxazine (Amplex™ Red reagent), a sensitive fluorogenic probe for hydrogen peroxide. AChE converts the acetylcholine substrate to choline, which is then oxidized by choline oxidase to betaine and hydrogen peroxide. In the presence of horseradish peroxidase, hydrogen peroxide reacts with the Amplex™ Red reagent in a 1:1 stoichiometric ratio to generate the highly fluorescent product resorufin.

Because resorufin has absorption and fluorescence emission maxima of approximately 571 nm and 585 nm, respectively, there is little interference from autofluorescence in most biological samples. Experiments with purified AChE from electric eel indicate that the Amplex™ Red Acetylcholine/Acetylcholinesterase Assay Kit can detect AChE levels as low as 0.002 U/mL using a reaction time of one hour. By providing an excess of AChE in the assay, the kit can also be used to detect acetylcholine levels as low as 0.3 μM, with a range of detection from 0.3 μM to 100 μM acetylcholine.

Use Amplex™ Red Assays for a Broad Range of Investigations
A wide variety of validated Amplex™ Red assays are available for studying cell signaling and lipids, neurobiology, inflammation and immune function, and metabolism. We also offer Amplex™ UltraRed Reagent (Cat. No. A36006), a second-generation reagent providing greater sensitivity and brighter fluorescence, and the Amplex™ Red/UltraRed Stop Reagent (Cat. No. A33855). The Amplex™ Red/UltraRed Stop Reagent provides convenience and control by allowing the fluorescence signal-generating reaction to be terminated at a user-determined time point. After addition of the stop reagent, the fluorescence signal remains stable for at least three hours. Custom assay design and packaging are also available.