title: Improved picoliter-sized micro-reactors for high-throughput biological analysis.
abstract: High-throughput pyrosequencing, carried out in millions of picoliter-sized reactors on a fiber-optic slide, is known for its longer read length. However, both optical crosstalk (which reduces the signal-to-noise ratio of CCD images) and chemical retention adversely affect the accuracy of chemiluminescence determination, and ultimately decrease the read length and the accuracy of pyrosequencing results. In this study, both titanium and oxidized aluminum films were deposited on the side walls and upper faces of micro-reactor slides to enhance optical isolation; the films reduced the inter-well crosstalk by one order of magnitude. Subsequently, chemical retention was shown to be caused by the lower diffusion coefficient of the side walls of the picoliter-sized reactors because of surface roughness and random pores. Optically isolated fiber-optic slides over-coated with silicon oxide showed smoother surface morphology, resulting in little chemical retention; this was further confirmed with theoretical calculations. Picoliter-sized micro-reactors coated with titanium-silicon oxide films showed the least inter-well optical crosstalk and chemical retention; these properties are expected to greatly improve the high-throughput pyrosequencing performance.
authors.affiliation: State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
authors.forename: WeiJing
authors.initials: W
authors.lastname: Han
authors.forename: LiNa
authors.initials: L
authors.lastname: Yuan
authors.forename: QingQuan
authors.initials: Q
authors.lastname: Wei
authors.forename: YunTao
authors.initials: Y
authors.lastname: Li
authors.forename: LuFeng
authors.initials: L
authors.lastname: Ren
authors.forename: XiaoGuang
authors.initials: X
authors.lastname: Zhou
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
authors.forename: YuDe
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000535:Aluminum; D020099:Coated Materials, Biocompatible; D059014:High-Throughput Nucleotide Sequencing / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D057166:High-Throughput Screening Assays / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D055100:Optical Fibers; D055620:Optical Phenomena; D017422:Sequence Analysis, DNA / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D059629:Signal-To-Noise Ratio; D012822:Silicon Dioxide; D013499:Surface Properties; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D012822:Silicon Dioxide; D000535:Aluminum; D014025:Titanium