Research

Accuracy and quality of massively parallel DNA pyrosequencing

Susan M Huse , Julie A Huber , Hilary G Morrison , Mitchell L Sogin and David Mark Welch

Josephine Bay Paul Center, Marine Biological Laboratory at Woods Hole, MBL Street, Woods Hole, MA 02543, USA

author email corresponding author email

Genome Biology 2007, 8:R143doi:10.1186/gb-2007-8-7-r143

Published:	20 July 2007

Subject areas: Genome studies, Methods

Abstract

Background

Massively parallel pyrosequencing systems have increased the efficiency of DNA sequencing, although the published per-base accuracy of a Roche GS20 is only 96%. In genome projects, highly redundant consensus assemblies can compensate for sequencing errors. In contrast, studies of microbial diversity that catalogue differences between PCR amplicons of ribosomal RNA genes (rDNA) or other conserved gene families cannot take advantage of consensus assemblies to detect and minimize incorrect base calls.

Results

We performed an empirical study of the per-base error rate for the Roche GS20 system using sequences of the V6 hypervariable region from cloned microbial ribosomal DNA (tag sequencing). We calculated a 99.5% accuracy rate in unassembled sequences, and identified several factors that can be used to remove a small percentage of low-quality reads, improving the accuracy to 99.75% or better.

Conclusion

By using objective criteria to eliminate low quality data, the quality of individual GS20 sequence reads in molecular ecological applications can surpass the accuracy of traditional capillary methods.