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Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to directly scan biological tissue sections slicing component maps. The storage of fresh tissue frozen sections; Discussion matrix type, concentration, covering method, developed stromal spray dedicated apparatus and method to optimize the the automatic scan parameters of the MS signal: 15mg/mL SA gradually spraying method, 15μm slice thickness 200μm lattice spacing, the laser energy of 30% to 50%, and 200 times the signal summation; optimizing the processing parameters and the mass peak in the original signal automatic statistical parameters. Self Software added two important features missing in the commercial software the \The results show that, the Hits The larger the value, the component is more widely distributed. Confirmed by the mass spectrum of imaging analysis of the reference substance, the composition distribution of the present method the positioning of the image is accurate. The more than 250 sections of over 40,000 mass spectra were obtained. The method is stable and feasible, the repeatability of better than 80%. SD rat pulmonary edema tissue (n = 16) and normal lung tissue (n = 15), t-test (P <0.05) screened 12 different molecules, which raised three, nine down, and raised downward molecule is closely related to its molecular weight, which was not observed in other organizations, it may be pulmonary edema disease specific. Create a classified prediction model under 12 difference in molecular mixed sample of 11 blind screening accuracy rate of 91% (10/11). Analysis of the human gastrointestinal stromal tumor tissue (n = 12) and normal tissues (12 cases), the t-test statistical methods, screening 16 statistically significant differences in the molecular (P <0.05), which up-regulated and 7 down. Create a classification prediction model under 16 difference in molecular mixed sample of eight blind sieve, the accuracy rate of 100%. In addition, statistics of the liver, pulmonary edema organizations, more than 7,000 of the three types of organizations gastrointestinal stromal tumor mass spectrometry imaging Figure summarized as follows image distribution law: (1) liver tissue: complementary, full screen (high-density type), in screen type (medium density type); (2) normal lung tissue: crescent, full screen, in screen type: (3) lung edema organizations: bow tie type, full screen, bow ties and complementary; ( 4) the normal gastrointestinal myometrium: full screen, peripheral, rare type; (5) Gastrointestinal Stromal Tumors: full screen, edge type, rare type. These distribution law is an important reference for further study of the development of the disease.
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