We are pleased to announce a new ELISA assay kit for the determination of free Ustekinumab. This new kit, Ustekinumab (Stelara®) ELISA Assay Kit has recently been added to our Research Drug Monitoring Assay Kit line which is a complete group comprised of a unique, versatile set of products for a variety of applications, research, and fields of study surrounding overall immunological health and immunological-related disorders.

What is Ustekinumab?

The drug Ustekinumab (trade name Stelara®) is a humanized immunoglobulin G1 kappa monoclonal antibody that binds with high specificity to the p40 protein subunit used by both the IL-12 and IL-23 cytokines. The ImmunoGuide Ustekinumab ELISA (mAb-based) kit can be efficiently used for measuring free Ustekinumab levels in serum and plasma.

Principle of the test

This ELISA is based on Ustekinumab-specific monoclonal antibody (catcher Ab, ImmunoGuide clone 9C7). Diluted standards and samples are incubated in the microtiter plate coated with IG-9C7 mAb. After incubation, the wells are washed. A biotinylated anti-human IgG monoclonal antibody (clone IG-1B5; specific for the Fc part of all human IgG i.e. IgG1, IgG2, IgG3 and IgG4) is added and binds to the Fc part of Ustekinumab. Following incubation, wells are washed and the horseradish peroxidase (HRP)-conjugated streptavidin is added and binds to the biotinylated 1B5 mAb. Following incubation, wells are washed and the bound enzymatic activity is detected by addition of chromogen-substrate. The color developed is proportional to the amount of Ustekinumab in the sample or standard. Results of samples can be determined by using the standard curve. Preincubation of Ustekinumab with recombinant human interleukin-12 (IL-12), contains p40 protein subunit as that of IL-23, inhibited the reaction. Therefore, the Ustekinumab ELISA (mAb-based) measures the free form of Ustekinumab.

*For Research Use Only. Not to be used in diagnostic procedures.

More information: Ustekinumab (Stelara®) (mAb-based) ELISA