Detection of single DNA molecules by multicolor quantum-dot end-labeling.

ABSTRACT: Observation of DNA-protein interactions by single molecule fluorescence microscopy is usually performed by using fluorescent DNA binding agents. However, such dyes have been shown to induce cleavage of the DNA molecule and perturb its interactions with proteins. A new method for the detection of surface-attached DNA molecules by fluorescence microscopy is introduced in this paper. Biotin- and/or digoxigenin-modified DNA fragments are covalently linked at both extremities of a DNA molecule via sequence-specific hybridization and ligation. After the modified DNA molecules have been stretched on a glass surface, their ends are visualized by multicolor fluorescence microscopy using conjugated quantum dots (QD). We demonstrate that under carefully selected conditions, the position and orientati

SUBMITTER: Crut A 

PROVIDER: S-EPMC1153714 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature