Human Chromogranin A (19-131) ELISA Kit Human Vasostatin-2 ELISA employs the quantitatively competitive enzyme immunoassay technique in which Human Vasostatin-2 present in samples competed with a fixed amount of biotinylated Human Vasostatin-2 for sites on purified rabbit IgG specific against Human Vasostatin-2. During the incubation, the rabbit IgG becomes bound to the goat anti-rabbit IgG pre-coated onto the microplates. Following a wash to remove any unbound antibody, standard, samples and biotin conjugate, a Streptavidin conjugated to horseradish- peroxidase (HRP) is added to the wells. After washing away any unbound enzyme, a substrate solution is added to the wells. The enzyme reaction yields a blue product that turns yellow when the Stop Solution is added. The intensity of the color measured is in proportion to the amount of Human Vasostatin-2 bound in the initial step. The sample values are then read off the standard curve. Human Vasostatin-2 ELSA has been shown to accurately quantitate the recombinant and natural Human Vasostatin-2. Results obtained using natural Human Vasostatin-2 showed dose response curves that were parallel to the standard curves obtained using the kit standards.