Multiplexing technologies are essential for the rapid screening of large numbers of samples in proteomic and genomic profiling. Tool providers are increasingly offering new solutions that feature ramped-up speed and efficiency. Other advances include disposable labware with improved plates for microarray screening, nanoparticle-based diagnostic tests, label-free systems, and multiplexing assays that identify small molecule drug candidates.
Corning Life Sciences manufactures a range of microwell plates for different multiplexing technologies. “The wide selection of products allows customers to evaluate their kits against different plates in order to choose that which will provide the optimum performance for a specific project,” says Mark Rothenberg, Ph.D., applications manager.
As current microarray technology typically takes advantage of either fluorescent and luminescent cell-based assays, investigators usually choose a black plate for fluorescent assays and a white plate for luminescent assays. Some protocols, however, call for a mixed fluorescent/luminescent combined assay, which is referred to as a multiplex kit. For this use, Dr. Rothenberg recommends a black plate in order to obtain minimal background noise, greater signal, and fewer false positives in both modes.
Tight budgets have forced many companies to search out the economic benefits of improved multiplexing devices. To this end, Corning has been adapting its product line to the demands of miniaturization, allowing for more rapid processing of samples at lower cost and with reduced sample requirements. According to Mike Briggs, Ph.D., product line manager, the 1,536-well plate is the flagship product this year. With its low volume requirements it can be used for a range of investigation, he says.
Nanosphere is focused on the development and commercialization of molecular diagnostic systems for ultrasensitive genomic and protein detection, says Winton Gibbons, vp for business development. “Our nanotechnology-based platform, the Verigene System, provides sensitivity for direct genetic and protein detection that is orders of magnitude higher than existing products.”
The Verigene System provides assays for flu, cancer, and cardiovascular and autoimmune diseases with a high multiplexing capability. “We believe that our system provides simple, inexpensive tests for genetic disorders as well as early detection of protein disease markers.”
The company has a number of different targets in the R&D stage, as well as FDA-approved tests for Warfarin metabolism, cystic fibrosis, and a first generation infectious respiratory disease assay. Additionally, Nanosphere is working with pharmaceutical and biotechnology firms to develop potential pharmacogenetic assays or companion diagnostics.
The Verigene equipment uses disposable test cartridges with a microarray format for high-count multiplex assays that insert into the microfluidics processor. The results are rapidly generated and there is no interpretation required, Gibbons notes.
The detection system is based on gold nanoparticle probes that bind to samples immobilized on microarrays. The nanoparticles are complexed with antibodies or with DNA probes depending on the particular test being performed. The protein-detection system can detect as low as zeptomolar levels of target.
“Through our nanotechnology approach, we are able to address the major limitations of existing technologies, providing lower cost and faster turnaround time with an easy-to-use platform. We have an extensive pipeline and portfolio with substantial rights to intellectual property from Northwestern University’s International Institute for Nanotechnology.”