5-Methyltetrahydrofolate (5-Me-THF) ELISA Kit: This assay employs the competitive inhibition enzyme immunoassay technique. A monoclonal antibody specific to 5-Me-THF has been pre-coated onto a microplate. A competitive inhibition reaction is launched between biotin labeled 5-Me-THF and unlabeled 5-Me-THF (Standards or samples) with the pre-coated antibody specific to 5-Me-THF. After incubation the unbound conjugate is washed off. Next, avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. The amount of bound HRP conjugate is reverse proportional to the concentration of 5-Me-THF in the sample. After addition of the substrate solution, the intensity of color developed is reverse proportional to the concentration of 5-Me-THF in the sample.