Luminex Multiplex Assay: Bead-Based Immunoassays
Luminex Multiplex utilizes xMAP technology comprising a magnetic or non-magnetic bead-based flow cytometric platform. The Luminex system creates unique spectral addresses for the microspheres by labeling them as per the different ratios of red and far-red fluorophores. This technology can detect multiple targets in a single immunoassay system by assigning each of them with a unique address through the covalent attachment of these fluorescent antibodies to the beads. Thus, this multiplexed immunoassay system with a microplate format can simultaneously analyze up to 100 different nucleic acids, proteins, or peptides.
By using the Luminex Multiplex platform, we can detect and quantitate multiple biomarker proteins in the provided samples to evaluate the safety and efficacy of your therapeutics. Furthermore, Luminex bead-based assays can be used in bioanalytical studies utilizing cell-based assays and biomarkers for cardiac, kidney, inflammation, cancer, apoptosis, toxicity, obesity, and intracellular cell signaling (including phosphoproteins and nucleic acids). High-performance multiplex assay kits available through this platform can be a valuable asset in basic and translational research on various diseases for the simultaneous analysis of multiple proteins, including growth factors and cytokines such as interferons, interleukins, chemokines, and members of the tumor necrosis superfamily.’
Step-by-step Luminex Multiplex Assay Protocol
Here’s a comprehensive protocol for Luminex Multiplex bead based assay –
- Incubate Luminex beads pre-coated with target-specific capture antibodies in a sample containing various target proteins
- Wash off the beads and incubate them again with target-specific biotinylated detection antibodies to sandwich the target proteins between the capture and detection antibodies
- Wash off the beads and incubate them with phycoerythrin (PE)-conjugated streptavidin (streptavidin-PE)
Generally, a chain is formed comprising the bead—target protein—fluorescent capture antibody—biotinylated target-specific antibody—streptavidin-PE when the samples contain a target of any given biotinylated antibody. Then, we draw a single-file of these Luminex beads into a flow cell to be excited by two lasers. This dual laser flow-based system identifies the signature of each bead and simultaneously detects the presence and intensity of the associated reporter (phycoerythrin). This Luminex Multiplex assay helps identify and quantitate targets in the sample as a high-speed digital signal processor manages the fluorescent output.