Patent ID: 8227196

Claim:
A method for determining an immunosuppressant drug in a sample suspected of containing an immunosuppressant drug, the method comprising: (a) providing in combination in a medium: (i) the sample, (ii) a hemolytic agent, and (iii) a bioavailability agent for the immunosuppressant drug, wherein the bioavailability agent is an ionic detergent comprising a chain of at least 10 carbon atoms or a non-ionic detergent comprising a chain of at least 15 repeating ethylene oxide units or propylene oxide units or a combination of ethylene oxide units and propylene oxide units and wherein the concentration of the bioavailability agent in the medium is sufficient to enhance the bioavailability of the hydrophobic drug by reducing interference from cholesterol and triglycerides, (b) incubating the medium under conditions for hemolyzing cells in the sample and for enhancing the bioavailability of the hydrophobic drug, (c) adding to the medium (i) magnetic particles comprising the immunosuppressant drug or an analog thereof and (ii) an antibody for the immunosuppressant drug comprising an enzyme, and (d) examining the medium for the presence of a complex comprising the immunosuppressant drug and the antibody for the immunosuppressant drug, the presence and/or amount of the complex indicating the presence and/or amount of the immunosuppressant drug in the sample.