双光子激发荧光成像技术对小鼠植入前胚胎的实时观测

Application of Two-Photon Excitation Fluorescence Imaging to Real-Time Investigation of Mouse Preimplantation Embryo

双光子激发的蓝移效应可使利用同一束超快激光同时激发多种不同荧光特性的生物荧光染料的设想得以实现。选取锁模飞秒掺钛蓝宝石(Ti-sapphire)激光器输出的730nm激光,分别激发Hoechst33342,Fluo-4,PI和Indo-1四种常用生物荧光染料,分别利用(455±15)nm,(540±15)nm,(580±16)nm和(500±15)nm四种滤光片获得特异性荧光图像。结合双光子激发荧光成像技术穿透深,光损伤小,信噪比好等优势,选取合适的荧光染料组,应用单束激光激发、双染双通道成像方法,对小鼠植入前胚胎内细胞中的钙信号和染色体进行三维、四维实时成像,为探究小鼠植入前胚胎发育规律提供一种全新的多参数观测手段。

The blue shift of a two-photon excitation absorption peak allows the application of a single wavelength to the simultaneous excitation of several fluorochromes with disparate emission characteristics. An output at 730nm of a mode-locked femtosecond Ti-sapphire laser was used to excite four different commonly used fluorochromes, namely Hoechst 33342, Fluo-4, PI and Indo-1, and characteristic fluorescence images were obtained using （455±15）nm, （540±15）nm, （580±16）nm and （500±15） nm filters respectively. An approach to exciting with a single wavelength, staining with two different fluorochromes, and collecting fluorescence in two separate channels was employed to study mouse preimplantation embryos by 3D and 4D real-time imaging. Combined with the merits of two-photon excitation fluorescence imaging, such as better penetration, less photon-damage, and higher signal-to-noise ratio, this approach was supposed to be a novel multi-parameter investigating tool for mouse preimplantation embryos development study.