MALDI-MS imaging of features smaller than the size of the laser beam
MALDI-MS imaging of features smaller than the size of the laser beam
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DOI：
10.1016/j.jasms.2005.06.006
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发表时间：
2005-10-01
影响因子：
3.2
通讯作者：
Sweedler, JV
中科院分区：
文献类型：
--
作者：
Jurchen, JC;Rubakhin, SS;Sweedler, JV
基质辅助激光解吸/电离质谱（MALDI-MS）成像小于激光束尺寸的功能的可行性已被证明。该方法包括在每个样品位置处完全烧蚀涂覆样品的MALDI基质，并在重复该过程之前将样品目标移动小于激光束直径的距离。在完全样品烧蚀的限制下，从间隔小于样品探针的距离的相邻位置获取信号增强了图像分辨率，因为测量的分析物信号仅由激光束尺寸和未烧蚀的样品表面的重叠产生。图像采集功能小于激光束的大小已被证明与肽标准沉积在电子显微镜校准网格和神经肽来源于单细胞。所提出的MS成像技术能够使用具有数百微米直径的不规则激光束尺寸的商业MALDI质谱仪实现类似于25 μ m的成像空间分辨率。通过适当的采样，激光束的大小对于可达到的MALDI-MS成像分辨率不是严格的障碍。
The feasibility of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging of features smaller than the laser beam size has been demonstrated. The method involves the complete ablation of the MALDI matrix coating the sample at each sample position and moving the sample target a distance less than the diameter of the laser beam before repeating the process. In the limit of complete sample ablation, acquiring signal from adjacent positions spaced by distances smaller than the sample probe enhances image resolution as the measured analyte signal only arises from the overlap of the laser beam size and the non-ablated sample surface. Image acquisition of features smaller than the laser beam size has been demonstrated with peptide standards deposited on electron microscopy calibration grids and with neuropeptides originating from single cells. The presented MS imaging technique enables similar to 25 mu m imaging spatial resolution using commercial MALDI mass spectrometers having irregular laser beam sizes of several hundred micron diameters. With appropriate sampling, the size of the laser beam is not a strict barrier to the attainable MALDI-MS imaging resolution.