Multi-Channel Episcopic Fluorescence Cryo-imaging System For Big Biological Sample

Fluorescence molecular imaging (FMI) has significantly advanced the understandingof molecular biology of tissue. The majority of research focuses on exogenous fluorescentmolecular labels, and they have advantages of convenience, high sensitivity and multitarget marked et al. With injection of the highly specified fluorescence molecular, FMIcan be use in detection of tissue information at cell even molecular level. Endogenousfluorescence in biological system offers the possibility to provide label-free read-outs ofbiological processes. Due to the high tissue absorption and scattering in the visiblespectrum range, it’s not feasible to acquire high resolution images for an entire organ ofmouse.In order to visualize expression/distribution of specific fluorescence agents andmeasure metabolic status of tissue, we developed a three-dimensional cryo-imagingsystem, which consists of grinding miller, electromagnetic radiation sources, imaginginstrument and XYZ sample positioner. Special instruments were designed to maintain thetemperature of the block face of the tissue using liquid nitrogen. The system allowssectioning and capturing bright-field and multi-channel endogenous and exogenousfluorescence images alternatively over tissue block face. Any Experiment involving themeasurement of fluorescence ranging from ultraviolet to NIR is capable for theinstrument.The system performance is analyzed and evaluated with phantom study. Theevaluation of the system includes tests of lateral resolution, detecting linearity andsensitivity. The results show that the system could acquire high resolution bright-field andmolecular fluorescence images for an entire organ with field view2×2cm~2with lateralresolution12.5μm and25.32μm，and detection sensitivity is at level of μM.The preliminary application of multi-channel microscopic cryo-imaging system isalso demonstrated. Tumor fromC57BL/6mouse targeted with KatushkaS158A whichspecifically express in tumor was imaged with the system. Information of metabolic states of tumor and distribution of KatushkaS158A was analyzed.3D volume of tumor wasconstructed through serial images.