The detection of neuropeptide Y (NPY) relies primarily on immunological methods, including enzyme-linked immunosorbent assay (ELISA) for quantitative analysis and immunohistochemistry (IHC) for tissue localization.
ELISA is a commonly used method for the quantitative determination of NPY levels in biological samples such as human serum, plasma, tissue homogenates, cell lysates, and cell culture supernatants. It typically employs a competitive inhibition principle: NPY monoclonal antibodies are coated onto a microplate, and both biotin-labeled antigen and the sample containing the target antigen are added. The target antigen competes with the labeled antigen for binding to the antibodies. Following a washing step, HRP-labeled avidin and the substrate TMB are added for color development; the intensity of the color is inversely proportional to the NPY concentration in the sample. This method offers high sensitivity and specificity, with a typical detection range of 24.69 pg/mL to 2000 pg/mL and a lower limit of detection below 9.59 pg/mL.
IHC is used to localize the expression and distribution of NPY within tissue sections. By utilizing specific antibodies to bind to NPY in the tissue and employing a chromogenic reaction for visualization, this method enables the qualitative or semi-quantitative analysis of NPY expression across different tissues.
