Abstract: The present disclosure provides methods and systems for nucleic acid sequencing. Such systems and methods may use a single flow cell to perform unbiased and/or biased sequencing to generate libraries of nucleic acid molecules. An aspect of the present disclosure provides a method for increasing complexity of a sample for sequencing, the method comprising: providing a first nucleic acid sample having a first degree of complexity that differs from a desired degree of complexity; providing a second nucleic acid sample having a second degree of complexity that differs from the first degree of complexity and that differs from the desired degree of complexity; pooling at least a portion of the first nucleic acid sample and at least a portion of the second nucleic acid sample, thereby generating a pooled nucleic acid sample having the desired degree of complexity; and sequencing at least a portion of the pooled nucleic acid sample.

Abstract: Disclosed are methods of manufacturing synthetic DNAs, that is, DNAs made at least in significant part by chemical synthesis of nucleic acid polymers. Also provided are methods for assembling plural DNAs in the same pool by multiplexed assembly of synthetic oligonucleotides. In exemplary embodiments, the methods involve pre-amplification of one or more oligonucleotides using “universal” primers, reduction of the error rate in oligonucleotide and/or nucleic acid products, and sequence optimization and oligonucleotides design. Also provided are low-purity arrays of nucleic acids and methods for assembling nucleic acids using oligonucleotides obtained from low-purity arrays.