Restoring single-molecule localizations with wavefront sensing adaptive optics for deep-tissue super-resolution imaging

Specimen-induced aberration has been one of the major factors limiting the imaging depth in single-molecule localization microscopy (SMLM). In this study, we measured the wavefront of intrinsic reflectance signal at the fluorescence emission wavelength to construct a time-gated reflection matrix and find complex tissue aberration without resorting to fluorescence detection. Physically correcting the identified aberration via wavefront shaping with a liquid-crystal spatial light modulator (SLM) enables super-resolution imaging even when the aberration is too severe for initiating localization processes. We demonstrate the correction of complex tissue aberration, the root-mean-square (RMS) wavefront distortion of which is more than twice the 1 rad limit presented in previous studies; this leads to the recovery of single molecules by 77 times increased localization number. We visualised dendritic spines in mouse brain tissues and early myelination processes in a whole zebrafish at up to 102 μm depth with 28-39 nm localization precision. The proposed approach can expand the application range of SMLM to thick samples that cause the loss of localization points owing to severe aberration.