Peptide YY 3 (PYY3) BioAssay-ELISA Kit (Human) employs the competitive inhibition enzyme immunoassay technique. An antibody specific for Peptide YY 3 (PYY3) has been pre-coated onto a microplate. A competitive inhibition reaction is launched between Horseradish Peroxidase (HRP) labeled Peptide YY 3 (PYY3) and unlabeled Peptide YY 3 (PYY3) (Standards or samples) with the pre-coated antibody specific for Peptide YY 3 (PYY3). After incubation the unbound conjugate is washed off. The amount of bound HRP conjugate is reverse proportional to the concentration of Peptide YY 3 (PYY3) in the sample. After addition of the substrate solution, the intensity of color developed is reverse proportional to the concentration of Peptide YY 3 (PYY3) in the sample.