Solexa Announces Progress in its Single Molecule Array Technology at BioArrays Europe Conference

Speaking at BioArrays Europe (Cambridge, UK, 30 Sept-1 Oct), Dr Tony Smith, Chief Technology Officer (CTO) of Solexa, presented data on the progress of the Company`s proprietary Single Molecule Array™ technology for human genetic variation applications, highlighting significant progress in the massively parallel detection of single molecules using fluorescence.

Solexa’s Single Molecule Array technology is being applied to the measurement of individual genetic variation to develop a method for complete personal genome sequencing called TotalGenotyping™. The Company’s technical approach combines proprietary advances in synthetic chemistry, surface chemistry, molecular biology, enzymology, array technology, optics, and informatics. The aim is to offer a potential five order of magnitude efficiency improvement, well beyond the range possible from existing technologies.

Commenting on their progress Dr Tony Smith said: “The progress we have made in the massively parallel detection of single molecules using fluorescence is a fundamental step forward in applying our Single Molecule Array technology towards a full working prototype. These discoveries take the company one step further towards its ultimate goal of ‘the thousand dollar genome’.”

Unlike conventional high-density arrays, Single Molecule Arrays are unaddressed and monodispersed: the sites on the surface are randomly distributed and at each there is only one single molecule (a fragment of DNA in the case of the sequencing application). Because there is only a single molecule at each site, it is possible to create arrays of very high site density, around 108 sites per cm2 or more, allowing massively parallel processing. By working at the single molecule level, Solexa’s method also avoids the need for amplification of target sequence, allowing ‘one-pot’ sample preparation for a whole genome analysis. It is the combination of these two features of ultra-high site density and amplification-free, one-pot sample preparation that creates the breakthrough in economics and throughput.

Solexa’s goal is to determine individual sequence variation compared to a reference sequence, rather than de novo sequencing. Solexa is currently developing a proprietary sequencing chemistry, SmaSeq™, that is compatible with its Single Molecule Arrays, and is also developing a proprietary bioinformatics system that aligns the sequencing output reads in the context of a reference system.

Solexa intends to use the massively parallel character of its technology to enable measurement of virtually all variation in a sample sequence. Its technology makes it significantly more economical to measure all variation in a sample rather than to select any large subset for analysis. Given the highly significant value of the additional information generated by TotalGenotyping, this is an extremely compelling approach.

To reach full working prototype, Solexa scientists will work on the integration of the various components of its technology into a sequencing system over the next 12 months.