Super-resolution imaging based on single molecule localization of cellular structures on nanometer scale requires to record a series of wide-field or TIRF images resulting in a considerable recording time (typically of minutes). Therefore, sample drift becomes a critical problem and will lower the imaging precision.
A research team led by Prof. HUANG Ruimin at Shanghai Institute of Materia Medica of Chinese Academy of Sciences utilized morphological features of the specimen (mammalian cells) itself as reference markers replacing the traditionally used markers (e.g., artificial fiduciary markers, fluorescent beads, or metal nanoparticles) for sample drift compensation. We achieved sub-nanometer localization precision <1.0 nm in lateral direction and <6.0 nm in axial direction, which is well comparable with the precision achieved with the established methods using artificial position markers added to the specimen. This method does not require complex hardware setup, extra labelling or markers, and has the additional advantage of the absence of photobleaching, which caused precision decrease during the course of super-resolution measurement. The achieved improvement of quality and resolution in reconstructed super-resolution images by application of our drift-correction method is demonstrated by single molecule localization-based super-resolution imaging of F-actin in fixed A549 cells.
△ Experimental setup and quantitative imaging to localize circular intracellular nanostructures
This work was published in Optics Express entitled “Three dimensional drift control at nano-scale in single molecule localization microscopy”. Dr. FAN Xiaoming at Shanghai Institute of Materia Medica of Chinese Academy of Sciences is the first author; Prof. HUANG Minrui is the corresponding author, who is also a doctoral supervisor at University of Chinese Academy of Sciencs.
