Patent ID: 8828671
Filing Date: 2014-09-09
Classification: G01N,Y10T

Abstract:
1. A method of determining drug binding for a drug administered to a subject, comprising: (a) isolating target-expressing cells from a biological sample obtained from a subject to whom a known amount of a drug has been administered, wherein the drug interacts with the target expressed by the target-expressing cells; (b) incubating the target-expressing cells with an anti-Total antibody and an anti-Free-Site antibody, wherein the anti-Total antibody and the anti-Free-Site antibody are monoclonal antibodies that bind specifically to different epitopes of the same target; (c) detecting the amount of the anti-Total antibody bound to the target-expressing cells of step (b), wherein the anti-Total antibody binds to an epitope on the target regardless of whether the target is also interacting with the drug; (d) detecting the amount of the anti-Free-Site antibody bound to the target expressing cells of step (b), wherein the anti-Free-Site antibody recognizes and binds to an epitope on the target when the drug is not interacting with the target but is competitively inhibited by the interaction of the drug with the target, wherein the amount of the anti-Total antibody detected in step (c) corresponds to the total amount of target expressed by the target-expressing cells and the amount of the anti-Free-Site antibody detected in step (d) corresponds to the total amount of drug-free target, and wherein the amount of drug-bound target is proportional to the amount of the anti-Total antibody detected in step (c) less the amount of the anti-Free-Site antibody detected in step (d).