Luminex’s xMAP suspension bead array systems have been widely adopted for research, drug discovery and IVD applications. The xMAP technology uses microscopic polystyrene beads as a carrier of a specific protein, antibody or nucleic acid. These beads are internally dyed using precise ratios of fluorophores, allowing researchers to detect specific reactions.

Luminex offers three systems that employ flow cytometry technology. The Luminex 100/200 system allows for multiplexing of 100 analytes in a single microplate well. Luminex also offers the FLEXMAP 3D, which is capable of multiplexing up to 500 unique assays within a single sample, and the MAGPIX system, which allows for up to 50 assays per sample. In the research market, Luminex relies on strategic partners such as Bio-Rad Laboratories and Millipore to distribute its systems and develop assays. In 2007, they sold more than 4,000 systems. Today, sales are approaching 10,000 units.

As popular as xMAP is, there are also other systems on the market that utilize the same fundamental concept for multiplexing assays. Illumina’s VeraCode technology employs glass microbeads that are embedded with digital holographic elements, allowing for the flexible design of bioassays for single or several hundred markers in a single well. Assays are analyzed with the BeadXpress reader.

Applied BioCode offers a platform using Barcode Magnetic Bead technology (BMB). BMB combines photolithographic digital barcodes with immuno- and molecular chemistry, giving a high-contrast signal and no fluorescence background. With near 100% decoding accuracy and up to 4,096 targets per assay, BMB is designed to improve identification and throughput capacity.

While other suspension bead array technologies are predominantly used for immunoassays, NanoString offers a system for gene expression. Its nCounter Analysis system profiles hundreds of mRNAs, miRNAs or DNA targets simultaneously. The system uses molecular barcodes and single-molecule imaging to detect and count up to 800 unique transcripts in one reaction. The technology employs a reporter and capture probe, which are about 50 bases each. The reporter probe carries the signal, while the capture probe allows the complex to be immobilized for data collection.

EBioscience, part of Affymetrix, offers the FlowCytomix system that employs flow cytometers from Becton Dickinson and Beckman Coulter, as well as Millipore and Miltenyi Biotec single-laser systems. The assay system can simultaneously quantify up to 20 protein targets. The company also offers the Procarta immunoassays, which are used on Luminex’s platform.

Suspension arrays continue to garner attention for research and IVD applications. While Luminex-based assays make up the majority of the market, other technologies offer unique advantages and increased capabilities. The total market for multiplex bead array instruments for research totaled about $35 million in 2012.

Suspension Array Systems

at a Glance:

Leading Suppliers

• Luminex

• Applied BioCode

• NanoString

Largest Markets

• Academia

• Government

• Pharmaceutical/Biotech

Instrument Cost

• $35,000–$75,000