Sherry Dunbar, Ph.D., director of scientific marketing at Luminex, observes that in recent years serum-based immunological assays designed to measure an antibody response to an analyte have been moving away from classical capture-based ELISA sandwich assay formats and toward a more direct, higher-throughput, and more easily automated assay design.
In addition to its two earlier flow cytometry-based analyzers—the Luminex 100/200™ and the Flexmap 3D systems—Luminex introduced the Magpix analyzer and MagPlex® superparamagnetic microspheres, to which an antigen of interest can be directly coupled. Assay processing, including analyte and reagent addition, washing, and detection, are performed via magnetic separation.
Whereas the Luminex 200 can process up to 100 different reactions per well and the Flexmap 3D analyzer has a multiplex capacity of up to 500 analytes per well, the Magpix was designed as a lower-cost, more compact option capable of multiplexed analysis of 1–50 analytes.
Once serum biomarker studies have moved beyond the discovery stage and have identified a subset of analytes relevant to a particular disease process or drug response, “for most applications people are looking at 30 or fewer analytes,” says Dr. Dunbar.
She describes the development of protein-based assays to detect antibodies indicative of exposure to an infectious disease or as a measure of vaccine efficacy as a growing area of interest in the clinical application of serum biomarker assays. Dr. Dunbar notes that the Luminex 200 has already been cleared by the FDA, with expectations of future FDA submissions for the Flexmap 3D and the Magpix systems.