Imaging Atmospheric Pressure MALDI Mass Spectrometry

描述（由申请人提供）：本提案的目的是开发一种新型仪器，用于使用大气压（AP）基质辅助激光解吸/电离（MALDI）质谱法（MS）以20-40 um的空间分辨率绘制组织切片中靶向化合物的分布。与真空MALDI相比，用于组织成像的AP MALDI方法具有诸如在大气条件下易于处理组织样品和当AP MALDI源与离子阱质谱仪连接时串联MS能力的重要优点。后者将为所研究的分子提供结构解析的能力，并通过在分析中增加1个MS维度来带来更好的特异性。该方案最重要的特点是使用波长为3 μ m的红外（IR）激光器代替紫外激光器进行离子解吸。AP IR-MALDI具有在不向样品中添加任何基质的情况下操作的潜力，使用通常存在于组织样品中的水分子作为基质，因此，大大简化了分析方案，并允许在没有基质干扰的情况下直接监测组织中的目标化合物。所提出的技术具有在生物学研究和临床研究的许多领域提供重要的分子信息的潜力。

DESCRIPTION (provided by applicant): The purpose of this proposal is to develop a novel instrument for mapping the distribution of targeted compounds in tissue sections with a spatial resolution of 20-40 um using atmospheric pressure (AP) matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). Compared to vacuum MALDI the AP MALDI approach for tissue imaging has such important advantages as easy handling of tissue samples at atmospheric conditions and a tandem MS capability when the AP MALDI source is interfaced to an ion trap mass spectrometer. The latter will provide capability of structural elucidation for molecules under study and bring better specificity via adding 1 more MS dimension into the analysis. The most important feature of this proposal is to use an infrared (IR) laser with the 3-um wavelength for ion desorption instead of an ultraviolet laser. AP IR-MALDI has the potential to operate without adding any matrix onto the sample, using water molecules normally present in the tissue sample as a matrix, thus, substantially simplifying the analysis protocol and allowing direct monitoring of targeted compounds in the tissues without matrix interferences. The proposed technology has a potential of providing important molecular information in many areas of biological research and clinical studies.