The proliferation of large-scale DNA-sequencing projects in recent years has driven a search for alternative methods to reduce time and cost. Here we describe a scalable, highly parallel sequencing system with raw throughput significantly greater than that of state-of-the-art capillary electrophoresis instruments. The apparatus uses a novel fibre-optic slide of individual wells and is able to sequence 25 million bases, at 99% or better accuracy, in one four-hour run. To achieve an approximately 100-fold increase in throughput over current Sanger sequencing technology, we have developed an emulsion method for DNA amplification and an instrument for sequencing by synthesis using a pyrosequencing protocol optimized for solid support and picolitre-scale volumes. Here we show the utility, throughput, accuracy and robustness of this system by shotgun sequencing and de novo assembly of the Mycoplasma genitalium genome with 96% coverage at 99.96% accuracy in one run of the machine.DNA sequencing has markedly changed the nature of biomedical research and medicine. Reductions in the cost, complexity and time required to sequence large amounts of DNA, including improvements in the ability to sequence bacterial and eukaryotic genomes, will have significant scientific, economic and cultural impact. Largescale sequencing projects, including whole-genome sequencing, have usually required the cloning of DNA fragments into bacterial vectors, amplification and purification of individual templates, followed by Sanger sequencing 1 using fluorescent chain-terminating nucleotide analogues 2 and either slab gel or capillary electrophoresis. Current estimates put the cost of sequencing a human genome between $10 million and $25 million 3 . Alternative sequencing methods have been described 4-8 ; however, no technology has displaced the use of bacterial vectors and Sanger sequencing as the main generators of sequence information.Here we describe an integrated system whose throughput routinely enables applications requiring millions of bases of sequence information, including whole-genome sequencing. Our focus has been on the co-development of an emulsion-based method 9-11 to isolate and amplify DNA fragments in vitro, and of a fabricated substrate and instrument that performs pyrophosphate-based sequencing (pyrosequencing 5,12 ) in picolitre-sized wells.In a typical run we generate over 25 million bases with a Phred quality score of 20 or better (predicted to have an accuracy of 99% or higher). Although this Phred 20 quality throughput is significantly higher than that of Sanger sequencing by capillary electrophoresis, it is currently at the cost of substantially shorter reads and lower average individual read accuracy. Sanger-based capillary electrophoresis sequencing systems produce up to 700 bases of sequence information from each of 96 DNA templates at an average read accuracy of 99.4% in 1 h, or 67,000 bases per hour, with substantially all of the bases having Phred 20 or better quality 23 . We further characterize the performance ...

Polymeric graphitic carbon nitride materials (for simplicity: g-C(3)N(4)) have attracted much attention in recent years because of their similarity to graphene. They are composed of C, N, and some minor H content only. In contrast to graphenes, g-C(3)N(4) is a medium-bandgap semiconductor and in that role an effective photocatalyst and chemical catalyst for a broad variety of reactions. In this Review, we describe the "polymer chemistry" of this structure, how band positions and bandgap can be varied by doping and copolymerization, and how the organic solid can be textured to make it an effective heterogenous catalyst. g-C(3)N(4) and its modifications have a high thermal and chemical stability and can catalyze a number of "dream reactions", such as photochemical splitting of water, mild and selective oxidation reactions, and--as a coactive catalytic support--superactive hydrogenation reactions. As carbon nitride is metal-free as such, it also tolerates functional groups and is therefore suited for multipurpose applications in biomass conversion and sustainable chemistry.

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