To compete with its illustrious rivals (Illumina, Life Technologies, Pacbio RS, Roche and SOLiD), Complete Genomics offers an original solution literally based on small DNA balls: each DNA fragment of the sequencing library is replicated hundreds of times finally resulting in a long DNA molecule made up of the same identical DNA fragment. Such molecule is then induced to consolidate in a small DNA nanoball of approximately 200 nanometers (here comes the name of the technique: DNA nanoball - DNBTM).
In such a DNA library the human genome is therefore made up of millions of nanoballs. These DNA nanoballs are then put on a silicon chip where each of them finds its place in a small "sticky spot". From this point, flourescence-based sequencing reaction starts: four different fluorescent-labeled probes are incorporated in a growing complementary DNA strand by a ligase enzyme depending on the sequence being read in the fragment. The sequence of the original library fragment is therefore reconstructed by imaging the fluorescence during each single base ligation step.
Output: according to the manufacturer it is possible to sequence up to two complete genomes per run at a capture 40x.
The workflow of the Complete Genomics platform is then completed by the bioinformatic analysis, which includes alignment and variant calling to identifiy SNPs, indels, copy number variations (CNVs), structural variants (SVs) and mobile element insertions (MEIs). The subsequent annotation step is also performed by the interrogation of publicly accessible databases.
For specific purposes of personalized medicine, this platform also offers the possibility to call variants based on paired tumor-normal tissue comparison.
Related subjects:
Related subjects:
