JWH-250 (K2/Spice) Synthetic Cannabinoid ELISA Assay Kit is based upon the competitive binding of JWH-250 and its metabolites in the test sample and JWH-250-conjugate (JWH-250 conjugated to horseradish peroxidase) to the anti- JWH-250-coated 96-well Microplate.
In the procedure, 20 µL aliquots of test samples (blanks, calibrators, quality control samples, and/or diluted unknown samples) are simultaneously incubated with 100 µL of JWH-250-conjugate in wells of a coated 96-well Microplate. The wells are washed thoroughly with Phosphate buffered saline, then TMB chromogenic substrate is added. A blue color is developed over 30 minutes at room temperature, and then stopped by the addition of dilute acid. The final yellow intensity of the wells is measured at OD450 nm, and the absorbance is inversely proportional to the concentration of JWH-250 and its metabolites in the sample. The limit of detection is approximately 5ng/mL for JWH-250 N-4-hydroxypentyl analogue, a major JWH-250 metabolite in human urine.