Patent ID: 6291184
Filing Date: 2001-09-18
Classification: A61K,B82Y,C07H,C07K,C12N,C12Q,C40B,F02B,G01N

Abstract:
A method for detecting the presence of a target molecule that is associated with a disease state in a biological substance which may contain said target molecule comprising:a) exposing a biological substance which may contain said target molecule that is associated with a disease state to a nucleic acid ligand identified according to the method comprising:i) identifying a nucleic acid ligand that photocrosslinks to a target molecule from a candidate mixture of nucleic acids, wherein each member of said candidate mixture contains a photoreactive group, said method comprising:1) contacting said candidate mixture of nucleic acids with a first biological substance which contains a target molecule that is associated with said disease state, wherein nucleic acids having an increased affinity to a molecule of said first biological substance relative to the candidate mixture form nucleic acid-molecule complexes with said molecule;2) irradiating said complexes, wherein said nucleic acid and molecule photocrosslink;3) partitioning the photocrosslinked nucleic acid-molecule complexes from the remainder of the candidate mixture; and4) identifying nucleic acid ligands that photocrosslink to said target molecule;ii) contacting a second biological substance which does not contain said target molecule that is associated with said disease state with said nucleic acid ligands identified in step 4), wherein the nucleic acids with affinity to a molecule that is not associated with the disease state in the second biological substance is removed; andiii) amplifying the remaining nucleic acids with specific affinity to said target molecule that is associated with a disease state to yield a mixture of nucleic acids enriched for nucleic acids with relatively higher affinity and specificity for binding to said target molecule that is associated with said disease state, whereby a nucleic acid ligand to a target molecule that is associated with a disease state in a biological substance is identified;b) irradiating said biological substance containing said nucleic acid ligand; andc) detecting whether a nucleic acid ligand-molecule complex has been formed, whereby said target molecule that is associated with said disease state is detected.