Living cell imaging by high resolution microscopy with two-photon excitation

In common fluorescence microscopy with one-photon excitations (OPE), the space resolution is about λ/2. Using femto-second (fs) laser, the two-photon excitation (TPE) can be achieved on the center part of the focused spot breaking the resolution limit producing the high resolution microscopy. In this work, the living cell imaging under OPE and TPE were comparatively measured. The autofluorescence interference of native fluorophores in living cells is serious under OPE, whereas the TPE of an 800 nm fs laser can produce a high space resolution images with good imaging quality by effectively eliminating the effect of autofluorescence.