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