The IDK® Arginine ELISA is intended for the quantitative determination of L-arginine in EDTA plasma.

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

For Laboratory Professional Use Only.

Developed by Immundiagnostik AG.

Test Principle of the IDK® Arginine ELISA

The IDK® Arginine ELISA is designed for the quantitative determination of L-arginine.

The assay is based on the method of competitive enzyme-linked immunoassays. The sample preparation includes the addition of a derivatization reagent for L-arginine derivatization. Afterward, the treated samples and a polyclonal L-arginine antiserum are incubated in the wells of a microtiter plate coated with L-arginine-derivative (tracer).

During the incubation period, the target L-arginine in the sample competes with the tracer, immobilized on the wall of the microtiter wells, for the binding of the polyclonal antibodies. During the second incubation step, a peroxidase-conjugated antibody is added to detect the anti-L-arginine 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 a photometer at 450 nm. The intensity of the yellow color is inversely proportional to the L-arginine concentration in the sample; this means, a high L-arginine concentration in the sample reduces the concentration of tracer-bound antibodies and lowers the photometric signal.

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