Multicomposite super‐resolution microscopy: Enhanced Airyscan resolution with radial fluctuation and sample expansions

Either modulated illumination or temporal fluctuation analysis can assist super‐resolution techniques in overcoming the diffraction limit of conventional optical microscopy. As they are not contradictory to each other, an effective combination of spatial and temporal super‐resolution mechanisms would further improve the resolution of fluorescent images. Here, a super‐resolution imaging method called fluctuation‐enhanced Airyscan technology (FEAST) is proposed, which achieves ~40 nm lateral imaging resolution and is useful for a range of fluorescent proteins and organic dyes. It was demonstrated not only to obtain different subcellular super‐resolution images, but also to improve the accuracy of counting the average human epidermal growth factor receptor 2 (HER2) copy number for diagnosis in breast cancer. Furthermore, the combination of FEAST and sample expansion microscopy (Ex‐FEAST) improves the lateral resolution to ~26 nm. A super‐resolution imaging method called fluctuation‐enhanced Airyscan technology (FEAST) is proposed by utilizing Airyscan imaging combined with fluctuation processing, which can achieve ~40 nm lateral imaging resolution (Figure B). Furthermore, FEAST combined with expansion microscopy (Ex‐FEAST) demonstrated the lateral optical resolution can be fourfold enhancement, which successfully depicted the hollow structure of microtubules (Figure D).