A specific and sensitive in vitro ELISA assay and diagnostic test kit is
disclosed for determining levels of NT-proBNP protein in a variety of
bodily fluids, non-limiting examples of which are blood, serum, plasma,
urine and the like. The NT-proBNP ELISA assay test employs the sandwich
ELISA technique to measure circulating NT-proBNP in human plasma. In
order to obtain antibodies with specific binding properties for targeted
amino acid sequences within human proBNP, recombinant human proBNP (or
rhproBNP) was expressed and purified for use as an immunogen. Polyclonal
antibodies (PAb) to specific amino acid sequences were subsequently
purified from goat serum by sequential affinity purification. Monoclonal
antibodies were raised against specific polypeptides. Recombinant human
NT-proBNP (or rhNT-proBNP) was expressed and purified in order to obtain
material for use in calibration of a quantitative method for measurement
of human NT-proBNP.