Immunoassay for toxic congeners of polychlorinated biphenyls

A method for determining qualitatively or quantitatively the presence of a toxic congener of polychlorinated biphenyl in a test sample comprising the steps of:

• A) providing a known quantity of antibodies to a toxic PCB congener comprising a congener lacking any chlorine substituent ortho to the bond linking the phenyl groups, a congener having only one chlorine substituent ortho to the biphenyl link or a combination thereof;
• B) providing a competitor that will bind to said antibodies in competition with the toxic PCB congener;
• wherein said competitor has one of the following structures:
• wherein
• (a) A is selected from the group consisting of —NH3—, —S—, —O—, —CH2—, —C(O)—, —CH═CH—, —NH—C(O)—, —C(O)—NH—, —NH—C(O)—NH—, —NH—C(S)—NH—, —N(CH3)—, —N(CH3)2—, and —OC(S)NH—;
• A′ is selected from the group consisting of —S—, —CH2—, —C(O)—, —CH═CH—, and —C(O)—NH—;
• (b) B is a single bond or an organic or inorganic linking group capable of forming covalent bonds with A and C simultaneously;
• (c) C is selected from the group consisting of —CO2H, —NH2, —CHO, and —OH;
• (d) Y and Y′ are selected from the group consisting of —H and —Cl;
• with the priviso that no more than one of Y and Y′ is —Cl;
• (e) n=0-5;
• (f) p=0-3;
• and
• (g) q=0-4;
• C) incubating said antibodies and said competitor in the presence of a test sample;
• and
• D) detecting the presence of the toxic PCB congener in the test sample.