IDK® Kynurenine ELISA

The IDK® Kynurenine ELISA is intended for the quantitative determination of L-kynurenine in human EDTA plasma, serum, and dried blood spots.

For research use only. Not for use in diagnostic procedures.

For Laboratory Professional Use Only.

Manufactured by Immundiagnostik AG.

Also available:

• Kynurenine ELISA High Sensitive (Mouse/Rat): KR3728
• IDO Activity ELISA: KR7726

Test Principle of the IDK® Kynurenine ELISA

The IDK® Kynurenine ELISA is designed for the quantitative determination of L-kynurenine. The assay is based on the method of competitive enzyme-linked immunoassays.

The sample preparation includes the addition of a derivatization reagent for kynurenine derivatization. Afterward, the treated samples and a polyclonal L-kynurenine-antiserum are incubated in the wells of a microtiter plate coated with L-kynurenine-derivative (tracer). During the incubation period, the target L-kynurenine in the sample competes with the tracer, immobilized on the wall of the microtiter wells, to bind the polyclonal antibodies.

During the second incubation step, a peroxidase-conjugated antibody is added to each microtiter well to detect the anti-kynurenine antibodies. After washing away the unbound components, tetramethylbenzidine (TMB) is added as a peroxidase substrate.

Finally, the enzymatic reaction is terminated by an acidic stop solution. The color changes from blue to yellow, and the absorbance is measured in the photometer at 450 nm. The intensity of the yellow color is inversely proportional to the L-kynurenine concentration in the sample; this means high L-kynurenine concentration in the sample reduces the concentration of tracer-bound antibodies and lowers the photometric signal.

A dose-response curve of absorbance unit (optical density, OD at 450 nm) vs. concentration is generated using the values obtained from the standards. The presence of L-kynurenine in the sample is determined directly from this curve.