Patent ID: 8524060

Claim:
A method of assaying an analyte in a liquid sample, comprising the steps of: (a) preparing a solution mixture comprising buffer solution, an analyte, a predefined concentration of a receptor specific to the analyte, and a known concentration of a fluorescent dye, wherein the receptor comprises a reporter species; (b) incubating the solution mixture, wherein the incubation is conducted under conditions sufficient to permit formation of a receptor-analyte immune complex, wherein a first part of the analyte is bound to a first part of the receptor and wherein a remaining second part of the receptor remains unbound; (c) introducing all or a portion of the solution mixture into a capillary separation system comprising a separation channel and a polyacrylamide gel comprising a step-wise or continuous gradient of polyacrylamide gel concentration; (d) applying an electric field between first and second ends of the capillary separation system to provide electrophoretic separation of the receptor from the receptor-analyte immune complex; (d) inducing a first signal response in the unbound receptor, a second signal response in the receptor-analyte immune complex and a third signal response in the fluorescent dye; (f) detecting and measuring each of the first, second and third signal responses as a series of electropherograms over time, wherein each electropherogram comprises a plurality of peaks corresponding to each of the first, second and third signal responses; and (g) comparing the areas beneath each of the peaks of each of the series of electropherograms to provide a dose response curve of the receptor-analyte immune complex.