for this type of hybrid genome assembly have been developed, such as the PacBio corrected Reads algorithm. There are inherent challenges when utilizing sequence reads from various technologies to assemble a sequenced genome; data coming from different sequencers can have different characteristics. An example of this can be seen when using the overlap-layout-consensus (OLC) method of genome assembly, which can be difficult when using reads of substantially different lengths. Currently, this challenge is being overcome by using multiple genome assembly programs. An example of this can be seen in Goldberg et al. where the authors paired 454 reads with Sanger reads. The 454 reads were first assemble using the Newbler assembler (which is optimized to use short reads) generating pseudo reads that were then paired with the longer Sanger reads and assembled using the Celera assembler. Hybrid genome assembly can also be accomplished using the Eulerian path approach. In this approach, the length of the assembled sequences does not matter as once a k-mer spectrum has been constructed, the lengths of the reads are irrelevant. Practical approaches Hybrid error correction and de novo assembly of single-molecule sequencing reads The authors of this study developed a correction algorithm called the PacBio corrected Reads (PBcR) algorithm which is implemented as part of the Celera assembly program. This algorithm calculates an accurate hybrid consensus sequence by mapping higher accuracy short reads (from second generation sequencing technologies) to individual lower accuracy long reads (from third-generation sequencing technologies). This mapping allows for trimming and correction of the long reads to improve the read accuracy from as low as 80% to over 99.9%. In the best example of this application from this paper, the contig size was quintupled when compared to the assemblies using only second-generation reads. This study offers an improvement over the typical programs and algorithms used to assemble uncorrected PacBio reads. ALLPATHS-LG (another program that can assemble PacBio reads) uses the uncorrected PacBio reads to assist in scaffolding and for the closing of gaps in short sequence assemblies. Due to computational limitations, this approach limits assembly to relatively small genomes (maximum of 10Mbp). The PBcR algorithm allows for the assembly of much larger genomes with higher fidelity and using uncorrected PacBio reads. This study also shows that using a lower coverage of corrected long reads is similar to using a higher coverage of shorter reads; 13x PBcR data (corrected using 50x Illumina data)