Phi29 DNA polymerase(Phi29 Pol)has emerged as a powerful tool in the third-generation sequencing technology such as DNA nanoball-based sequencing.However,natural Phi29 Pol with low amplification activity under high-sa...Phi29 DNA polymerase(Phi29 Pol)has emerged as a powerful tool in the third-generation sequencing technology such as DNA nanoball-based sequencing.However,natural Phi29 Pol with low amplification activity under high-salt conditions needs to be engineered to meet specific sequencing demands,which are usually achieved through a time-consuming and iterative trial-and-error process.Herein,we develop a high-throughput screening methodology for efficiently detecting Phi29 Pol mutants with high rolling-circle amplification(RCA)efficiency under high-salt conditions.The method uses a nucleic acid gel stain sensitive to oligonucleotides to achieve the input conversion from enzymatic amplification efficiency to fluorescence intensity in micron-sized droplets.We further demonstrate the potential of this methodology in the first high-throughput droplet sorting of Phi29 Pol.The RCA efficiency of sorted mutant S6 is 1.39-fold that of initial enzyme M2 in 300 mM KCl.Overall,this study provides a cost-effective and rapid solution for improving the performance of Phi29 Pol under high-salt conditions.展开更多
We report the investigation on the performance of an amplification assisted difference frequency generation(AA-DFG) system driven by pulsed pump and continuous-wave primary signal lasers. A monolithic tandem lithium n...We report the investigation on the performance of an amplification assisted difference frequency generation(AA-DFG) system driven by pulsed pump and continuous-wave primary signal lasers. A monolithic tandem lithium niobate superlattice was employed as the nonlinear crystal with a uniform grating section for the DFG process, followed by a chirp section for the optical parametric amplification process. The impacts of pump pulse shape, primary signal power, input beam diameter, and crystal structure on the pump-to-idler conversion efficiency of the AA-DFG system were comprehensively studied by numerically solving the coupled wave equations. It is concluded that square pump pulse and high primary signal power are beneficial to high pump-to-idler conversion efficiency. In addition, tighter input beam focus and smaller DFG length proportion could redeem the reduction in conversion efficiency resulting from wider acceptance bandwidths for the input lasers. We believe that such systems combining the merits of high stability inherited from cavity-free configuration and high efficiency attributed from the cascaded nonlinear conversion should be of great interest to a wide community,especially when the pulse shaping technique is incorporated.展开更多
Ultra-high-speed, ultra-large-capacity and ultra-long-haul （3U） are the forever pursuit of optical communication. As a new mode of optical communication, 3U transmission can greatly promote next generation optical i...Ultra-high-speed, ultra-large-capacity and ultra-long-haul （3U） are the forever pursuit of optical communication. As a new mode of optical communication, 3U transmission can greatly promote next generation optical internet and broadband mobile communication network development and technological progress, therefore it has become the focus of international high-tech intellectual property competition ground. This paper introduces the scientific problems, key technologies and important achievements in 3U transmission research.展开更多
基金supported by the National Key Research and Development Program of China(2022YFC3401303)Shandong Province Key R&D Program(Major Science and Technology Innovation Project)Project(2023CXGC010714)+1 种基金Natural Science Foundation of Jiangsu Province(BK20240202)Key Technological Project of Jiangxi Province(20244AFH82001)。
文摘Phi29 DNA polymerase(Phi29 Pol)has emerged as a powerful tool in the third-generation sequencing technology such as DNA nanoball-based sequencing.However,natural Phi29 Pol with low amplification activity under high-salt conditions needs to be engineered to meet specific sequencing demands,which are usually achieved through a time-consuming and iterative trial-and-error process.Herein,we develop a high-throughput screening methodology for efficiently detecting Phi29 Pol mutants with high rolling-circle amplification(RCA)efficiency under high-salt conditions.The method uses a nucleic acid gel stain sensitive to oligonucleotides to achieve the input conversion from enzymatic amplification efficiency to fluorescence intensity in micron-sized droplets.We further demonstrate the potential of this methodology in the first high-throughput droplet sorting of Phi29 Pol.The RCA efficiency of sorted mutant S6 is 1.39-fold that of initial enzyme M2 in 300 mM KCl.Overall,this study provides a cost-effective and rapid solution for improving the performance of Phi29 Pol under high-salt conditions.
基金National Natural Science Foundation of China(NSFC)(61505236)Key Laboratory Foundation of Chinese Academy of Sciences(CAS)(CXJJ-15S099,CXJJ-17S026)Innovation Foundation of Shanghai Institute of Technical Physics(CX-54)
文摘We report the investigation on the performance of an amplification assisted difference frequency generation(AA-DFG) system driven by pulsed pump and continuous-wave primary signal lasers. A monolithic tandem lithium niobate superlattice was employed as the nonlinear crystal with a uniform grating section for the DFG process, followed by a chirp section for the optical parametric amplification process. The impacts of pump pulse shape, primary signal power, input beam diameter, and crystal structure on the pump-to-idler conversion efficiency of the AA-DFG system were comprehensively studied by numerically solving the coupled wave equations. It is concluded that square pump pulse and high primary signal power are beneficial to high pump-to-idler conversion efficiency. In addition, tighter input beam focus and smaller DFG length proportion could redeem the reduction in conversion efficiency resulting from wider acceptance bandwidths for the input lasers. We believe that such systems combining the merits of high stability inherited from cavity-free configuration and high efficiency attributed from the cascaded nonlinear conversion should be of great interest to a wide community,especially when the pulse shaping technique is incorporated.
文摘Ultra-high-speed, ultra-large-capacity and ultra-long-haul （3U） are the forever pursuit of optical communication. As a new mode of optical communication, 3U transmission can greatly promote next generation optical internet and broadband mobile communication network development and technological progress, therefore it has become the focus of international high-tech intellectual property competition ground. This paper introduces the scientific problems, key technologies and important achievements in 3U transmission research.
