Patent ID: 7569358

Claim:
An immunoassay for determining the amount of doxorubicin in a human sample comprising providing a mixture of a) said sample, b) an antibody selectively reactive with doxorubicin and not substantially cross-reactive with doxorubicin aglycone and c) a known amount of a conjugate of a carrier having either a reactive thiol or amino group with either a compound of the formula: wherein A is Y is an organic spacing group; X is a functional group capable of binding to said carrier through said amino or thiol group; and p is an integer from 0 to 1; or a compound of the formula: wherein X, Y and p are as above and B is or a mixture of a known amount of the conjugates formed from the compound of formula II-A and II-B as described above, wherein said conjugate competes with said doxorubicin in the sample for binding sites on said antibody; and allowing the doxorubicin in the sample and said conjugate in said mixture to competitively bind in said mixture with said antibody and thereafter measuring the amount of said conjugate in said mixture which is bound to said antibody to determine the amount of doxorubicin in the sample, wherein the measured amount of said conjugate bound to said antibody is inversely proportional to the amount of doxorubicin present in the sample.