In a paper recently published in Genome Biology, Robert Nicol and colleagues from the Broad Institute in Massachusetts, report a new method for reducing the time and cost associated with 454 sequencing.
The recent revolution in next-generation sequencing technologies impacted significantly on the genomics field, dramatically reducing the cost of sequencing large genomes, such as those of mammals – the recently published giant panda genome was sequenced entirely using Illumina short-read sequence data. However, this reduction in cost is less apparent for small or medium-sized genomes, where to run a single lane or channel on a sequencer would result in a vast over-coverage of sequence data, reducing the cost-effectiveness of the process. In addition, manual preparation of the DNA library prior to sequencing is labour-intensive and time consuming, and also introduces the possibility of researcher error, all of which increases the overall cost.
The new paper describes the optimization of a series of methods for sample preparation and introduces a new technique for adding short ‘barcode’ sequences to the start of the DNA fragments. This allows each DNA library to be identified uniquely, meaning more than one library can be mixed together and run on the same sequencer channel, bringing the cost of sequencing several smaller genomes within the reach of labs with smaller budgets. These new technologies should result in a further increase in the rate at which new genomes are being sequenced.