Sub-diffraction dark spot localization microscopy

Abstract

Recently, a new technique called MINFLUX was promoted and attained ~1-nanometer precision. However, MINFLUX is incapable of discerning two molecules within the diffraction-limited region unless with the help of on-off switching scheme of SMLM which yet entails time-consuming processes. Here, we produce a novel kind of focal spot pattern, called sub-diffraction dark spot, to localize molecules within the sub-diffraction region of interest. In our proposed technique nominated as sub-diffracted dark spot localization microscopy (SDLM), multiple molecules within the diffraction-limited region could be distinguished without the requirement of fluorescent switches. We have numerically presented the SDLM modality and some impacts, like intensity, are investigated. Simulative localization framework has been implemented on randomly-distributed and specifically-structured samples. SDLM is evidenced to have high localization accuracy and stability in densely-packed fluorescent solution.