The IDKmonitor® Ustekinumab Drug Level ELISA is an enzyme immunoassay intended for the quantitative determination of free therapeutic ustekinumab antibodies (e.g. STELARA®) in EDTA plasma and serum.

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 9660.

We also offer the IDKmonitor® Ustekinumab Free ADA ELISA.

Test Principle of the IDKmonitor® Ustekinumab Drug Level ELISA

The IDKmonitor® Ustekinumab Drug Level ELISA is designed to determine the quantity of free ustekinumab (therapeutic antibody against interleukins 12 and 23) in EDTA plasma or serum samples.

In the first incubation step, the free ustekinumab from the sample is bound to the specific monoclonal anti-ustekinumab antibody coated on the plate. After a washing step, ustekinumab bound to the plate is detected by adding a peroxidase-labeled anti-ustekinumab antibody. Tetramethylbenzidine (TMB) is used as a substrate for peroxidase.

Finally, an acidic stop solution is added to terminate the reaction. The color changes from blue to yellow. The intensity of the yellow color is directly proportional to the concentration of free ustekinumab in the sample.

A dose-response curve of the absorbance unit (optical density, OD) vs. concentration is generated using the values obtained from the standard. The concentrations of free ustekinumab in the samples are determined directly from this curve.