The SPRimager®II array reader is a label-free, SPR-based platform developed by GWC Technologies. Voula Kodoyianni, Ph.D., CSO, reports that the system “delivers a compelling combination of efficient throughput and experimental robustness.”
She says that the technology is among the most versatile of molecular detection systems, given that it is label free, monitors multiple interactions simultaneously, and acts independently of the chemistry of the molecules or the reactions that they may enter into.
“There is no need to modify the molecules with fluorescent or other tags that might compromise their function,” she adds. “Furthermore, and this is not generally appreciated, the technology provides real-time data, enabling the investigator to monitor the progress of binding without disturbing the molecular interaction.”
As is standard practice in such systems, the SPRimager II reads interactions occurring on gold-coated chips to which molecules may be covalently attached or bound through affinity interactions such as streptavidin-biotin complexes.
Producing the arrays is straightforward and can be done through hand-pipetting using the company’s SpotReady™ chips, or, for higher density arrays, with the aid of a robotic spotter using plain gold SPRchip™ substrates. Solutions containing analytes are washed through the flow cell of the reader over the arrayed molecules and molecular associations can be monitored as changes in reflectivity as a function of time.
GWC Technologies is collaborating with Lloyd Smith, Ph.D., professor in the department of chemistry at the University of Wisconsin, who has developed an amorphous carbon covering to protect the gold surface of the chip.
Conventional gold-coated chips are acknowledged to be fragile and can delaminate under harsh conditions such as with the use of strongly alkaline or acidic solutions. The amorphous carbon layering technology provides a much more robust surface and allows a wider variety of chip modifications to be performed, Dr. Kodoyianni says, including direct on-chip synthesis of oligonucleotides and other oligomeric biomolecules of interest. Such approaches dramatically reduce costs and increase efficiency of array fabrication.