A small startup near San Francisco has recently completed a pilot-assessment study of a novel and little-known high-throughput SNP-genotyping platform and has begun shopping around for commercialization partners.
The company, Quantum Dot, hopes the results of the study will lead to a second phase for its existing semiconductor-nanocrystal technology. It may already have a leg-up on rival SNP-detecting companies: its technology was validated with financial and logistical help from GlaxoSmithKline, the granddaddy of SNP research and pharmacogenomics.
The technology, called Qbead, uses Quantum Dot’s fluorescent semiconductor nanocrystals called Qdots, or quantum dots, to encode microspheres that are used as platforms for multiplexed assays. According to Quantum Dot, combining mixtures of quantum dots with emission wavelengths creates unique spectral “barcodes” that “enable ... high levels” of multiplexing.
“We applied the Qbead system to SNP genotyping by encoding microspheres conjugated to allele-specific oligonucleotides,” the company said in a study published in the current issue of Nucleic Acids Research. After the oligonucleotide probes on the microspheres hybridize to PCR amplicons in the sample, individual microspheres are analyzed by flow cytometry and each SNP is distinguished by its unique spectral barcode, the company said.
In the study, Quantum Dot and Glaxo used 10 model SNPs to validate the Qbead system and called it “an accurate and reliable technique for multiplexed SNP genotyping.” The company added: “By modifying the types of probes conjugated to microspheres, the … system can … be adapted to other assay chemistries for SNP genotyping as well as to other applications such as analysis of gene expression and protein-protein interactions.”
Quantum defines its Qdots as “molecular-scale optical beacons” that “behave like molecular LEDs by ‘lighting up’ biological-binding events with … applied colors.” Furthermore, researchers can use standard conjugation chemistry to covalently link Qdots to biomolecules, the company reports. “This Qdot conjugate can then be used to detect its binding partner in a wide range of assays.”
Qdots, which are currently on the market, also have potential applications in gene expression, genotyping, and proteomics, according to Joel Martin, chairman of Quantum. The Qbeads product, meantime, is in later-stage development. Martin, who is also a venture capitalist at Forward Ventures in San Diego, said Quantum Dot has been negotiating with “a couple of different partners” to commercialize the platform, but stressed that GlaxoSmithKline is not one of them.
Quantum Dot, founded in November 1998, is located in Hayward, Calif., and employs approximately 50 people. To date, the company has raised around $37.5 million in financing from venture groups Versant Ventures, Abingworth Management, Technogen Associates, Schroder Ventures, Frazier & Co, MPM Asset Management, and CMEA Ventures.
“The company now is at the stage of development where we hope it will be, based on its sales and its collaborative efforts, self-sustained,” Martin told SNPtech Reporter. There may be investment in the future to bunt growth, but for the moment there’s no immediate plans.”
Though the Glaxo research deal did not involve “huge financial collaborations, they were important technology-validation and information-gathering explorations,” said Martin.
He said neither Glaxo nor Genentech, another collaborative partner, is in the running to help Quantum roll out the Qbead. Martin said that these kinds of companies — big biopharma — would instead be considered customers.
Meanwhile, Glaxo’s team found the Qbead technology to have “worked very well as a [SNP]-detection technology, and that it enhanced our genotyping capabilities and … advanced our research at that time,” according to a Glaxo spokeswoman.
Asked whether Glaxo is planning on becoming a Qbead customer, the spokeswoman said “it would depend on our research needs. We’re always open to the best pathways that’s available to us to accomplish what we need, and we certainly depend on companies like Quantum for their technology.”
— KL