Infrared Laser Ablation Sample Transfer for MALDI Imaging
Infrared Laser Ablation Sample Transfer for MALDI Imaging
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DOI：
10.1021/ac3006704
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发表时间：
2012-04-03
影响因子：
7.4
通讯作者：
Murray, Kermit K.
中科院分区：
文献类型：
--
作者：
Park, Sung-Gun;Murray, Kermit K.
在环境条件下使用红外激光器从组织切片烧蚀材料，以直接收集在基质辅助激光解吸电离（MALDI）靶上。将10 μ m厚的组织样品置于显微镜载玻片上，并将组织侧向下安装在第二显微镜载玻片的70和450 μ m之间。将两个载玻片安装在平移台上，并在聚焦的中红外（IR）激光束下二维扫描组织，以通过消融将材料转移到靶载玻片上。将材料转移到靶载玻片后，使用串联飞行时间质谱仪使用MALDI成像对其进行分析。从用于系统初始优化的肽标准品和使用沉积到基质预涂靶上或在样品转移后加入基质的小鼠脑组织切片获得图像，并与标准MALDI质谱成像的图像进行比较。转移材料的空间分辨率约为400 μ m。激光烧蚀样品转移提供了几种传统MALDI成像不可能的新能力，包括（1）用于MALDI成像的环境采样，（2）烧蚀材料的面积到斑点浓度，（3）用于多次成像分析的材料收集，以及（4）直接收集到纳米结构辅助激光解吸电离（NALDI）靶上而无需印迹或切片。
An infrared laser was used to ablate material from tissue sections under ambient conditions for direct collection on a matrix assisted laser desorption ionization (MALDI) target. A 10 mu m thick tissue sample was placed on a microscope slide and was mounted tissue-side down between 70 and 450 mu m from a second microscope slide. The two slides were mounted on a translation stage, and the tissue was scanned in two dimensions under a focused mid-infrared (IR) laser beam to transfer material to the target slide via ablation. After the material was transferred to the target slide, it was analyzed using MALDI imaging using a tandem time-of-flight mass spectrometer. Images were obtained from peptide standards for initial optimization of the system and from mouse brain tissue sections using deposition either onto a matrix precoated target or with matrix addition after sample transfer and compared with those from standard MALDI mass spectrometry imaging. The spatial resolution of the transferred material is approximately 400 mu m. Laser ablation sample transfer provides several new capabilities not possible with conventional MALDI imaging including (1) ambient sampling for MALDI imaging, (2) area to spot concentration of ablated material, (3) collection of material for multiple imaging analyses, and (4) direct collection onto nanostructure assisted laser desorption ionization (NALDI) targets without blotting or ultrathin sections.