Superresolution imaging of DNA tetrahedral nanostructures in cells by STED method with continuous wave lasers

DNA tetrahedral nanostructures are considered to be new nanocarriers because they can be precisely controlled and hold excellent penetration ability to the cellular membrane.Although the DNA tetrahedral nanostructure is extensively studied in biology and medicine,its behavior in the cells with nanoscale resolution is not understood clearly.In this letter,we demonstrate superresolution fluorescence imaging of the distribution of DNA tetrahedral nanostructures in the cell with a simulated emission depletion(STED)microscope,which is built based on a conventional confocal microscope and can provide a resolution of 70nm.