Lifetime super-resolution optical fluctuation imaging.

Abstract

In this paper, we propose a promising super-resolution imaging scheme in fluorescence lifetime domain (lifetime super-resolution optical fluctuation imaging, ltSOFI). ltSOFI has the potential to obtain super-resolution images by taking advantage of fluorescence lifetime blinking under wide-field lifetime detection. The proof-of-concept for ltSOFI was demonstrated through numerical simulation of high-order cumulant analysis on fluorescence lifetime blinking emitters. As a tentative experimental demonstration, we obtained super-resolution lifetime imaging from time-lapse FLIM recording of HeLa cells expressing a cAMP sensor using ltSOFI method. ltSOFI is expected to initiate a new dimension in the lifetime domain for blinking-based super-resolution microscopy. LAY DESCRIPTION: We report on a promising super-resolution imaging scheme in fluorescence lifetime domain (lifetime super-resolution optical fluctuation imaging, ltSOFI). ltSOFI has the potential to obtain super-resolution images by taking advantage of fluorescence lifetime blinking under wide-field lifetime detection. Past advances in super-resolution fluorescence microscopy primarily rely on the spatiotemporal modulation of the fluorescence intensity. Although the applications of the Q-dot blinking have been discussed in the literature, most of the discussions have focused on the blinking of fluorescence intensity. Few studies have shown the possibility of super-resolution imaging through fluorescence lifetime fluctuations. In this paper, we proposed the ltSOFI scheme that explored the possibility of super-resolution reconstruction from the blinking of fluorescence lifetime. The proof-of-concept for ltSOFI was demonstrated through numerical simulation of high-order cumulant analysis on fluorescence lifetime blinking emitters. As a tentative experimental demonstration, we obtained super-resolution lifetime imaging from time-lapse FLIM recording of HeLa cells expressing a cAMP sensor using ltSOFI method. The ltSOFI method is expected to initiate a new dimension in the lifetime domain for blinking-based super-resolution microscopy. Moreover, the existing fluorescence lifetime imaging microscopy and super-resolution nanoscopy can benefit from the implementation of ltSOFI to significantly improve the imaging spatial resolution of fluorescence lifetime images. In addition, the proof-of-concept demonstration achieved by the numerical simulation and tentative experiment will provide a new perspective for obtaining fluorescence lifetime images with much finer details.