DNA molecules were stretched on silanized mica surface with the molecular combing technique, and detected with fluorescence microscopy and atomic force microscopy. Meantime, DNA molecules were stretched with a modifie...DNA molecules were stretched on silanized mica surface with the molecular combing technique, and detected with fluorescence microscopy and atomic force microscopy. Meantime, DNA molecules were stretched with a modified dynamic molecular combing technique and studied with atomic force microscopy. The results indicate that, compared with the dynamic molecular combing technique, the modified dynamic molecular combing technique has advantages of less-sample demand and less contamination to sample; as compared with the molecular combing technique, it has better aligning effect and reproducibility. Combination of this kind of DNA molecular manipulating technique with the single DNA molecule detecting technique by atomic force microscopy and fluorescence microscopy will play an important role in the basic research of molecular dynamics and the application of gene research.展开更多
Anticoagulation factor I (ACF I) from the venom of Agki^strodon acutus is a binding protein to activated coagulation factor X (FXa) and possesses marked anticoagulant activity. Single ACF I molecule has been succe...Anticoagulation factor I (ACF I) from the venom of Agki^strodon acutus is a binding protein to activated coagulation factor X (FXa) and possesses marked anticoagulant activity. Single ACF I molecule has been successfully imaged in air by tapping mode atomic force microscopy (AFM) with high resolution using glutaraldehyde as a coupling agent. The physical adsorption and covalent binding of ACF I onto the mica show very different surface topographies. The former exhibits the characteristic strand like structure with much less reproducibility, the latter displays a elliptic granular structure with better reproducibility, which suggests that the stability of ACF I molecules on the mica is enhanced by covalent bonding in the presence of glutaraldehyde. A small scale AFM amplitude mode image clearly shows that the covalently bonded ACF I molecule by glutaraldehyde has olive shape structure with an average size of 7 4 nm×3 6 nm×3 1 nm, which is very similar to the size determined from the crystal structure of ACF I.展开更多
原子力显微镜(Atomic force microscopy,AFM)及荧光显微镜(Fluorescence microscopy,FM)是目前活细胞单分子分析检测中最常用的两种工具。结合两种显微镜的优势,发展高时空分辨、多功能的AFM-FM联用技术成为近年该领域的研究热点。本文...原子力显微镜(Atomic force microscopy,AFM)及荧光显微镜(Fluorescence microscopy,FM)是目前活细胞单分子分析检测中最常用的两种工具。结合两种显微镜的优势,发展高时空分辨、多功能的AFM-FM联用技术成为近年该领域的研究热点。本文简述了AFM单分子力谱和FM单分子荧光成像的原理,总结了AFM-FM联用系统在仪器研制方面的发展概况,并结合本课题组在应用AFM-FM联用技术研究细胞膜上配受体相互作用等方面的工作,介绍了其在活细胞单分子检测中的应用进展。展开更多
文摘DNA molecules were stretched on silanized mica surface with the molecular combing technique, and detected with fluorescence microscopy and atomic force microscopy. Meantime, DNA molecules were stretched with a modified dynamic molecular combing technique and studied with atomic force microscopy. The results indicate that, compared with the dynamic molecular combing technique, the modified dynamic molecular combing technique has advantages of less-sample demand and less contamination to sample; as compared with the molecular combing technique, it has better aligning effect and reproducibility. Combination of this kind of DNA molecular manipulating technique with the single DNA molecule detecting technique by atomic force microscopy and fluorescence microscopy will play an important role in the basic research of molecular dynamics and the application of gene research.
文摘Anticoagulation factor I (ACF I) from the venom of Agki^strodon acutus is a binding protein to activated coagulation factor X (FXa) and possesses marked anticoagulant activity. Single ACF I molecule has been successfully imaged in air by tapping mode atomic force microscopy (AFM) with high resolution using glutaraldehyde as a coupling agent. The physical adsorption and covalent binding of ACF I onto the mica show very different surface topographies. The former exhibits the characteristic strand like structure with much less reproducibility, the latter displays a elliptic granular structure with better reproducibility, which suggests that the stability of ACF I molecules on the mica is enhanced by covalent bonding in the presence of glutaraldehyde. A small scale AFM amplitude mode image clearly shows that the covalently bonded ACF I molecule by glutaraldehyde has olive shape structure with an average size of 7 4 nm×3 6 nm×3 1 nm, which is very similar to the size determined from the crystal structure of ACF I.
文摘原子力显微镜(Atomic force microscopy,AFM)及荧光显微镜(Fluorescence microscopy,FM)是目前活细胞单分子分析检测中最常用的两种工具。结合两种显微镜的优势,发展高时空分辨、多功能的AFM-FM联用技术成为近年该领域的研究热点。本文简述了AFM单分子力谱和FM单分子荧光成像的原理,总结了AFM-FM联用系统在仪器研制方面的发展概况,并结合本课题组在应用AFM-FM联用技术研究细胞膜上配受体相互作用等方面的工作,介绍了其在活细胞单分子检测中的应用进展。
