Multiplex (assay) - Example Multiplex Assay Techniques - Protein-based Multiplex Techniques

Protein-based Multiplex Techniques

• Protein microarray for measuring protein-protein interactions or small molecule binding
• Antibody microarray a type of protein array in which antibodies are arrayed
• Phage display for screening large protein libraries for interacting proteins or other molecules
• Antibody profiling (e.g. multiple HLA antibody identification or reactivity prediction against a panel of organ donor population): Luminex/XMAP principle based muliplexing is done for Anti-HLA antibody identification in serum samples where a mixture of color-coded luminex beads are coated either in such a way that individual beads (PRA beads) carry HLA peptide libraries from individual donors thus in combination simulating a donor population (for Panel reactive antibody or PRA testing), or single purified synthetic HLA antigens captured onto the beads (single antigen beads).
• Luminex/XMAP is bead based multiplexing, where beads are internally dyed with fluorescent dyes to produce a specific spectral address. Biomolecules (such as an oligo or antibody) can be conjugated to the surface of beads to capture analytes of interest. This technology uses flow cytometric or imaging technologies for characterization of the beads as well as detection of phycoerythrin emission due to analyte presence. The Luminex technology enables up to 500 proteins or genes to be detected in each well of a 96 or 384-well plate, using very small sample volume. Common applications include cytokines, metabolic markers, and phosphorylated proteins.