Helicos’ True Single Molecule Sequencing(tSMS)™ technology helps researchers to directly sequence the single molecules of DNA or RNA, significantly increases the speed of sequencing, while also decreasing the cost. Recently it was used for single-molecule DNA sequencing of a viral genome which was published in April edition of journal Science. Yesterday another publication appeared in the on-line edition of Nature describing successful development of direct RNA sequencing (DRS), allowing massively parallel sequencing of RNA molecules directly without prior synthesis of cDNA or the need for ligation/amplification steps which means unlike other transcript analysis technologies this approach is not subjected to the limitations associated with reverse transcriptases behaviour, amplification, ligation and other cDNA synthesis/sample manipulation steps.
How it works
Check out the video for a better idea

Within two flow cells, billions of single molecules of sample DNA are captured on an application-specific proprietary surface. These captured strands serve as templates for the sequencing-by-synthesis process:

Polymerase and one fluorescently labeled nucleotide (C, G, A or T) are added.

* The polymerase catalyzes the sequence-specific incorporation of fluorescent nucleotides into nascent complementary strands on all the templates.
* After a wash step, which removes all free nucleotides, the incorporated nucleotides are imaged and their positions recorded.
* The fluorescent group is removed in a highly efficient cleavage process, leaving behind the incorporated nucleotide.
* The process continues through each of the other three bases.
* Multiple four-base cycles result in complementary strands greater than 25 bases in length synthesized on billions of templates—providing a greater than 25-base read from each of those individual templates.