Read filtering and selection prior to assembly to avoid inclusion of reads containing sequencing errors. (A) Proportion of correct reads that remain in the data set by applying two- to fourfold redundancy filtering (i.e., by counting reads present at least twice, threefold, or fourfold in the data set) depending on BAC pool size (average insert size per BAC 110 kbp). (B) Proportion of false reads that remain in the data set for assembly after application of two- to fourfold redundancy filtering. Data were simulated with 0.6% error rate.