日本Luminex xMAP Technology
The rapidly growing knowledge base in drug discovery and protein research has placed increased pressure on researchers to rapidly obtain and analyze systems-level data sets connecting proteins and pathways to biological states. Increasingly, this information is difficult or impractical to obtain using traditional “singleplex” protein detection methods, such as ELISA or Western blotting.Luminex xMAP technology, the basis for Millipore’s MILLIPLEX MAP system, is a particularly powerful platform for simultaneous, “multiplex” detection of proteins in a single biological sample. Luminex xMAP technology is one of the fastest growing and most respected multiplex technologies and is applied throughout the life sciences, including clinical diagnostics.
Systems using xMAP technology perform a variety of bioassays including immunoassays on the surface of fluorescent-coded beads known as microspheres, which are then read in a compact analyzer. Using flow cytometry-based bead isolation, two lasers and high-speed digital-signal processors, the analyzer reads signals on each individual microsphere particle. The capability of adding multiple conjugated beads to each sample results in the ability to obtain multiple results from each sample. Open-architecture xMAP technology enables multiplexing of many types of bioassays reducing time, labor and costs over traditional methods.
Traditional Luminex instrumentation quantifies fluorescent signals from each bead using flow cytometry, the new MAGPIX instrument takes advantage of a new lighting and detection mechanism to reduce costs and improve reliability. Unlike flow cytometry which leverages the physics of fluid flow to align beads single file through a cuvette, where they can be illuminated with higher cost lasers, MAGPIX flows beads with considerably less fluid volume into a chamber. There they are held in a monolayer with a magnet. Lower-cost LEDs are focused on the chamber to illuminate the beads, which are imaged using a CCD camera. Image processing algorithms are run to deliver the assay results.
Comparing the principles underlying flow cytometry-based (top) and LED/image-based instruments (bottom) for Luminex xMAP technology.
How does Luminex xMAP technology compare with other assay platforms?
Due to robust multiplexing capabilities, Luminex xMAP technology has the potential to deliver more data in less time than other assay platforms, with comparable results to ELISA and microarrays. Luminex xMAP technology offers several other distinct advantages over traditional methods:- Speed/High Throughput — Because each microsphere serves as an individual test, a large number of different assays can be performed and analyzed simultaneously
- Versatility — A single xMAP technology-based system can perform assays in several different formats, including nucleic acids and antigen-antibody binding, along with enzyme, receptor-ligand and other protein interactions
- Flexibility — The technology can be customized for the user’s specific needs based upon their analytes of interest
- Accuracy — The technology generates real-time analysis and accurate quantification of the biological interactions
- Reproducibility — High-volume production of xMAP microspheres within a single lot allows assay standardization that solid-phased flat arrays cannot provide
- Traditional ELISA, real-time PCR and other technologies that excel at high-throughput applications (greater than 1000 samples per day) lack the ability to multiplex more than 5 tests at a time.
- Microarray technology excels in high-density screening (greater than 250-plex tests) — but lacks the reproducibility needed for high-throughput applications.
