Multi-photon (or two-photon microscopy) takes advantages of the near simultaneous absorption of two or more photons which act to excite a fluorescent molecule with the combined energy of both photons. In practice this means that low energy infrared light can be used to see fluorescent molecules that are normally excited by high energy ultraviolet and blue light. Using this method we can visualize fluorescent molecules at much greater depths than conventional microscopy. Infrared light is also much less damaging to live tissues than UV or blue excitation, making it ideal for visualizing model organisms or tissue explants. The Leica SP5 MP HyD combines both confocal and multi-photon modes in a single machine and can easily switch between different modalities. It is also fitted with the brand new, super-sensitive external HyD hybrid detectors dedicated for multi-photon microscopy.
>> Deep tissue imaging: imaging thicker tissue sections (>100 microns) and complex models such as Zebrafish where GFP is used as a marker
>> Long term live imaging: where UV or Blue illumination would be toxic (IR light is much less damaging)
>> High resolution intravital imaging: Often used in near -surface tissues such as skin, retina and brain
>> Quantitative photoactivation: multiphoton-excitation only activates mole-cules in the focal plan unlike conventional fluorescence
>> Fluorescence properties of novel materials: For example nanoparticles often exhibit special absorbance and fluorescence properties when excited by two photon activation