Ustekinumab ELISA (STELARA)

Intended Use:This Ustekinumab ELISA is a rapid and easy method for the quantitative determination of Ustekinumab in human serum, plasma and cell culture supernatant. Assay Background:Ustekinumab is a human monoclonal antibody. It is directed against interleukin 12and interleukin 23, naturally occurring proteins that regulate the immune system and immune-mediated inflammatory disorders. In two Phase III trials for moderate to severe psoriasis, the longest >76 weeks, Ustekinumab was safe and effective. A third Phase III trial, ACCEPT, compared the efficacy and safety of Ustekinumab with etanercept in the treatment of moderate to severe plaque psoriasis. This trial found a significantly higher clinical response with Ustekinumab over the 12-week study period compared to high-dose etanercept. It also demonstrated the clinical benefit of Ustekinumab among patients who failed to respond to etanercept. Ustekinumab is approved in Canada, Europe and the United States to treat moderate to severe plaque psoriasis. Assay Principle:The method employs the quantitative sandwich enzyme immunoassay technique. Antibodies to Ustekinumab are pre-coated onto microwells. Samples and standards are pipetted into microwells and human Ustekinumab present in the sample are bound by the capture antibody. Then, a HRP (horseradish peroxidase) conjugated anti- Ustekinumab antibody is pipetted and incubated with samples. After washing microwells in order to remove any nonspecific binding, the ready to use substrate solution (TMB) is added to microwells and color develops proportionally to the amount of Ustekinumab in the sample. Color development is then stopped by addition of stop solution. Absorbance is measured at 450 nm.