Fluorescence images of actin filaments in HeLa cell spheroids in SPA-SIM mode for two-photon activation
Description
Fluorescence images of actin filaments in living HeLa cell spheroids visualized with rsGamillus-S were obtained using selective-plane-activation structured illumination microscopy (SPA-SIM) with two-photon activation by a Bessel sheet. In the SPA-SIM system the aberrations make the imaging deeper parts difficult and limit the imaging depth to approximately 69 micrometre in a spheroid of ~200 micrometre in diameter. rsGamillus-S is an acid-resistance photoswitchable fluorescent protein, which owns exceptionally high on-switching rate to show the nuclei more clearly. Two-photon activation using a scanned Bessel beam produces a wider FOV and a higher axial resolution.