What is a Luminex Assay?

A Luminex® assay is a type of immunoassay that precisely measures multiple analytes in one sample. The Luminex xMAP® technology is a bead-based immunoassay that allows for multiplex detection of up to 500 analytes simultaneously. Color-coded microspheres, or beads, are internally dyed with different proportions of red and infrared fluorophores that correspond to a distinct spectral signature, or bead region.

Antibodies specific to a desired analyte are coupled to a unique bead region and are incubated with sample. After washing away unbound materials, samples are incubated with a mixture of biotinylated detection antibodies and a streptavidin-phycoerythrin (PE) reporter. Using a Luminex instrument, beads are excited by one laser to determine the bead region and corresponding assigned analyte. Another laser determines the magnitude of the PE-derived signal, which is proportional to the amount of analyte bound. Multiple readings are taken at each bead region, ensuring robust detection.

Luminex Assay Principle

Assay Principle. Luminex assays use a set of fluorescent beads where each bead falls in a unique spot on the fluorescent spectrum. The beads are coated with capture antibody targeted to the analyte of interest.

Illustration of steps 1 and 2 of the Luminex Assay

Step 1. The sample is added to a mixture of color-coded beads, pre-coated with analyte-specific capture antibodies. The antibodies bind to the analytes of interest.

Step 2. Biotinylated detection antibodies specific to the analytes of interest are added and form an antibody-antigen sandwich. Phycoerythrin (PE)-conjugated streptavidin is added. It binds to the biotinylated detection antibodies.

Illustration of step 3 of the Luminex Assay

Step 3. A magnet in the Luminex instrument captures and holds the magnetic beads in a monolayer, while two spectrally distinct light-emitting diodes (LEDs) illuminate the beads. One LED identifies the analyte that is being detected and the second LED determines the magnitude of the PE-derived signal. Each well is imaged with a CCD camera.

Benefits of Luminex Multiplex Assays

Small Sample Volume: Conserves sample by measuring multiple analytes in a single well with less than 50 µL of sample.
Save Time and Money: Save resources when compared to running multiple single-analyte ELISAs.
Flexibility: Build analyte panels to fit your research needs.
Low Variability: Minimizes experimental variability with multiple data points derived from a single experiment.

Benefits of R&D Systems Luminex Assays

R&D Systems’ Luminex assays have the largest, most flexible Luminex analytes available.  With our menu of off-the-shelf fixed panels, high-performance configurable panels, and completely custom panels, we have options to best fit your needs, ensuring you get the most data from your samples with results you can trust.

Selection: Flexibility of panels and formats available.
Experience: High Performance Luminex Assays are correlated to the gold standard Quantikine ELISA.
Availability: Fast delivery times.
Superior Quality Control:Assays undergo multiple quality control steps during production ensuring long-term reproducibility and consistency.
Specific: Assays for each target analyte are screened against all target analytes to confirm low antibody cross-reactivity.
Validation: High performance panels are extensively validated for optimal performance.
Versatile: Antibody pairs are tested to confirm parallel detection of natural and recombinant proteins.
Custom Services: Expert custom team available to help meet your unique needs.