[Development of a simple method of detecting acetaminophen using 96 well microplate readers]

Acetaminophen (APAP: N-Acetyl-p-aminophenol) has been widely used as a relatively safe antipyretic and analgesic drug. However, APAP is known as a major causative agent of fulminant hepatic failure, in a dose and a blood concentration dependent manner, in Western countries. The APAP toxicity should be expected to increase in proportion as the increasing of the clinical use in Japan. Therefore, a simplified method which determines the concentration of APAP would be valuable for clinical use. We have modified the APAP determination method developed by Yasojima. Our method enabled to measure APAP concentration with a small volume of samples by using 96-well microtiter plate, which can handle multiple samples simultaneously. From 10 microg/ml to 320 microg/ml of APAP was quantitatively measured by our method, which is suitable for diagnostics of the APAP toxicity. APAP levels below the lethal concentration of 160 microg/ml can be determined with one plate.