Patent ID: 8455212

Claim:
An immunoassay method for quantifying the amount of human NT-pro B-type natriuretic peptide (“human NT-proBNP”), human pro B-type natriuretic peptide (“human proBNP”) and human brain natriuretic peptide (“hBNP”) in a test sample being tested for or suspected of containing human NT-proBNP, human proBNP and hBNP, the immunoassay method comprising the steps of: (a) contacting a test sample with (i) a first capture antibody that binds to human NT-proBNP and that has been immobilized onto a solid phase to produce a first immobilized antibody and forming a first mixture comprising a first capture antibody-human NT-proBNP complex; (ii) a second capture antibody that binds to human proBNP and that has been immobilized onto a solid phase to produce a second immobilized antibody and forming a second mixture comprising a second capture antibody-human proBNP complex; and (iii) the second capture antibody, which in addition to binding to human proBNP also binds hBNP, and that has been immobilized onto a solid phase to produce a third immobilized antibody and forming a third mixture comprising a second capture antibody-hBNP complex, wherein said first capture antibody comprises antibody 151F11 and the second capture antibody comprises antibody 8.1; (b) contacting said first mixture comprising the first capture antibody-human NT-proBNP complex with a first detection antibody which binds to human NT-proBNP and that has been conjugated to a first detectable label to form a fourth mixture comprising a first capture antibody-human NT-proBNP-first detection antibody complex, wherein the first detection antibody is 15C4; (c) contacting the second mixture comprising the second capture antibody-human proBNP complex with the first detection antibody which, in addition to binding to human NT-proBNP, also binds to human proBNP, and that has been conjugated to the first detectable label to form a fifth mixture comprising a second capture antibody-human proBNP-first detection antibody complex, wherein the first detection antibody is antibody 15C4; (d) contacting the third mixture comprising the second capture antibody-hBNP complex with a second detection antibody which binds hBNP and that has been conjugated to a second detectable label to form a sixth mixture comprising a second capture antibody-hBNP-second detection antibody complex, wherein the second detection antibody is antibody 201.3; and (e) determining the amount of (i) first capture antibody-human NT-proBNP-first detection antibody complex formed in step (b) by detecting the first detectable label as a measure of the amount of human NT-proBNP contained in the test sample; (ii) the second capture antibody-human proBNP-first detection antibody complex formed in step (c) by detecting the first detectable label as a measure of the amount of human proBNP contained in the test sample; and (iii) the second capture antibody-hBNP-second detection antibody complex formed in step (d) by detecting the second detectable label as a measure of the amount of hBNP contained in the test sample.