The GABA ELISA (Stool) is intended for the quantitative detection of the concentration of free gamma-aminobutyric acid (GABA) in stool.

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 7009.

We also offer a GABA ELISA for use with plasma, serum, and urine.

Test Principle of the GABA ELISA (Stool)

The GABA ELISA (Stool) is based on the method of competitive enzyme-linked immunoassays. The sample preparation includes the addition of a derivatization reagent for GABA derivatization. Afterward, the treated samples and a peroxidase-conjugated polyclonal GABA antibody are incubated in wells of a microtiter plate coated with GABA derivative (tracer). During the incubation period, the target GABA in the
sample competes with the tracer, immobilized on the wall of the microtiter wells, for the binding of the polyclonal 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 GABA concentration in the sample. This means a high GABA concentration in the sample reduces the concentration of tracer-bound antibody 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. GABA, present in the patient samples, is determined directly from this curve.