EaStCHEM School of Chemistry , University of Edinburgh , Edinburgh , United Kingdom EH9 3FJ.
School of Biomedical Sciences , University of Ulster , Coleraine , United Kingdom BT52 1SA.
Anal Chem. 2018 Aug 7;90(15):8742-8749. doi: 10.1021/acs.analchem.8b00670. Epub 2018 Jul 27.
Successful matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) relies on the selection of the most appropriate matrix and optimization of the matrix application parameters. In order to achieve reproducible high spatial-resolution imaging data, several commercially available automated matrix application platforms have become available. However, the high cost of these commercial matrix sprayers is restricting access into this emerging research field. Here, we report an automated platform for matrix deposition, employing a converted commercially available 3D printer ($300) and other parts commonly found in an analytical chemistry lab as a low-cost alternative to commercial sprayers. Using printed fluorescent rhodamine B microarrays and employing experimental design, the matrix deposition parameters were optimized to minimize surface analyte diffusion. Finally, the optimized matrix application method was applied to image three-dimensional MCF-7 cell culture spheroid sections (ca. 500 μm diameter tissue samples) and sections of mouse brain. Using this system, we demonstrate robust and reproducible observations of endogenous metabolite and steroid distributions with a high spatial resolution.
成功的基质辅助激光解吸电离（MALDI）质谱成像（MSI）依赖于选择最合适的基质和优化基质应用参数。为了获得可重现的高空间分辨率成像数据，已经出现了几种商业上可用的自动化基质应用平台。然而，这些商用基质喷雾器的高成本限制了该新兴研究领域的发展。在这里，我们报告了一种用于基质沉积的自动化平台，该平台使用了经过改装的商业上可用的 3D 打印机（300 美元）和分析化学实验室中常见的其他部件，作为商用喷雾器的低成本替代方案。使用打印的荧光罗丹明 B 微阵列，并采用实验设计，优化了基质沉积参数，以最小化表面分析物的扩散。最后，将优化的基质应用方法应用于成像三维 MCF-7 细胞培养球体切片（约 500 μm 直径的组织样本）和小鼠脑切片。使用该系统，我们展示了具有高空间分辨率的内源性代谢物和类固醇分布的稳健且可重现的观察结果。
