Therapeutic agents, including antibodies and proteins, have been widely used to treat cancer, inflammation, allergy, and other diseases. Monitoring drug antibody (DA) level has been critical to determine the optimal dose for clinical treatment. Especially knowing the kinetics of DA level is important for evaluation of DA efficacy and safety. Testing DA level combined with testing anti-drug antibody (ADA) level can help determine whether ADA in individuals affect DA efficacy. The RayPlex® DA Bead Assay is a sandwich- and bead-based fully quantitative assay for the detection of one or multiple DAs using small sample volumes. It features high sensitivity, high stability, and high throughput with the reliable flow cytometry methodology. RayPlex® DA Bead Assay requires no dedicated instrument and can be performed on most standard flow cytometers equipped with blue (PE) and red (APC) lasers.
RayPlex® DA Assays are tested as antibody bridge model. First ADAs are immobilized onto microbeads. After incubating the sample with the microbeads, DAs are captured on the bead surface, and biotinylated same ADAs are added, followed by PE-conjugated streptavidin. This enables protein detection via the PE-streptavidin-biotin-antibody complex. In a multiplex setting, individual DAs are identified by their specific bead populations, while the level of PE fluorescence reflects the amount of DA that has been captured to the beads. The DA level can be assessed (i.e., quantified) by comparing the PE signal to a standard curve generated from DA standards at known concentrations.
Upon receipt, all components should be stored at 4°C. Use reagents immediately after preparation. Additional vials of the Liquid Standard (Item 5) can be purchased separately. If stored at the proper temperature, the kit will retain complete activity for at least 6 months.
