The SDMA ELISA is intended for the quantitative determination of symmetric dimethylarginine (SDMA) in human, canine and feline serum, EDTA, and Li-heparin plasma.

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

For Laboratory Professional Use Only.

This is the RUO version of Immundiagnostik part number K 7780.

Test Principle of the SDMA ELISA

The SDMA ELISA is designed for the quantitative determination of SDMA. The assay is based on the method of competitive enzyme-linked immunoassays.

The sample preparation includes the addition of a derivatization reagent for SDMA derivatization. Afterward, the treated samples and the polyclonal SDMA antiserum are incubated in wells of a microtiter plate coated with SDMA derivative (tracer).

During the incubation period, the target SDMA 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-SDMA 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 SDMA concentration in the sample; this means high SDMA 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 SDMA in the samples is determined directly from this curve.