An estimate of large-scale sequencing accuracy

The accuracy of large-scale DNA sequencing is difficult to estimate without redundant effort. We have found that the mobile genetic element IS10, a co mponent of the transposon Tn10, has contaminated a significant number of cl ones in the public databases, as a result of the use of the transposon in b acterial cloning strain construction. These contaminations need to be annot ated as such. More positively, by defining the range of sequence variation in IS10, we have been able to determine that the rate of sequencing errors is very low, most likely surpassing the stated aim of one error or less in ten thousand bases.