Super-localization of individual fluorophores along a DNA strand in a microchannel

DNA mapping is a method of stretching random-coiled DNA molecules and then analyzing them using a fluorescence microscope. This method has been used for DNA analyses. In this study, to realize more accurate DNA analyses with small amounts of samples, we aimed to stretch and immobilize lambda DNA molecules and to achieve super-resolution imaging with the direct stochastic optical reconstruction microscopy (dSTORM) of a single lambda DNA molecule in a microchannel. To stretch and immobilize the DNA molecule, we used an air-water interface movement by controlling the pressure in the microchannel. The DNA molecule was stretched and immobilized on an air-plasma-treated glass substrate, which prevented the overlapping of the DNA molecules owing to the small adhesion force, and a stretching ratio of 75% was achieved. We performed dSTORM imaging with the blinking of YOYO-1 dyes along the DNA molecule in the microchannel with the width of 200 mu m, the depth of 2 mu m, and the length of 40 mm. We obtained the super-resolution imaging of the DNA molecule with the full width at half maximum of 67 nm. The design of microchannel is required to improve dSTORM imaging of DNA molecules, and the issue could be explored in our future studies. Published under an exclusive license by AIP Publishing.

Automated summary

This study focused on stretching and immobilizing lambda DNA molecules in a microchannel to achieve super-resolution imaging using dSTORM. By controlling pressure in the microchannel and utilizing YOYO-1 dye blinking, they successfully obtained super-resolution imaging with a half maximum width of 67 nm. Improving the design of the microchannel is essential for enhancing dSTORM imaging of DNA molecules in future studies.