Patent ID: 9534036
Date: 2017-01-03
CPC Classifications: C07K,G01N

Claim:
1. A method for detecting a platelet-derived shed ectodomain of a CD31 protein, a lymphocyte-derived shed ectodomain of a CD31 protein, and a soluble splice variant of said CD31 protein in a biological sample, wherein said platelet-derived shed ectodomain of a CD31 protein is a CD31 fragment (i) comprising the 1 st to 5 th extracellular immunoglobulin (lg)-like domains and the whole or a part of the 6 th extracellular lg-like domain of said full-length CD31 protein, said part of the 6 th extracellular lg-like domain comprising an amino acid sequence corresponding to residues 494 to 501 of human CD31 protein and (ii) not comprising the intracellular domain of said full-length protein, the method comprising: a) providing a capture antibody wherein said capture antibody specifically binds to an epitope located in a region that is present on said platelet-derived shed ectodomain, on said lymphocyte-derived shed ectodomain and on said splice variant; b) providing a first discriminating antibody which specifically binds to an epitope located in a region that is present on said platelet-derived shed ectodomain and said splice variant and absent from said lymphocyte-derived shed ectodomain; c) providing a second discriminating antibody which specifically binds to an epitope located in a region that is present on said splice variant and absent from said platelet-derived shed ectodomain and from said lymphocyte-derived shed ectodomain; d) providing a third discriminating antibody which specifically binds to an epitope located in a region that is present on said platelet-derived shed ectodomain, on said lymphocyte-derived shed ectodomain and on said splice variant; wherein said discriminating antibodies are labeled with a detectable label; e) contacting said antibodies with the biological sample; f) measuring the signal obtained from the label associated with each discriminating antibody; wherein the capture antibody and the third discriminating antibody bind within the region defined by the 1 st , 2 nd , 3 rd , 4 th and 5 th extracellular domains of said CD31, the first discriminating antibody binds within the 6th Ig-like extracellular domain of said CD31, and the second discriminating antibody binds to the intracellular domain of said CD31.