OligoTag: a program for designing sets of tags for next-generation sequencing of multiplexed samples.

Next-generation sequencing systems allow high-throughput production of DNA sequence data. But this technology is more adapted for analyzing a small number of samples needing a huge amount of sequences rather than a large number of samples needing a small number of sequences. One solution to this problem is sample multiplexing. To achieve this, one can add a small tag at the extremities of the sequenced DNA molecules. These tags will be identified using bioinformatics tools after the sequencing step to sort sequences among samples. The rules to apply for selecting a good set of tags adapted to each situation are described in this chapter. Depending on the number of samples to tag and on the required quality of assignation, different solutions are possible. The software oligoTag, a part of OBITools that computes these sets of tags, is presented with some example sets of tags.