Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
J Am Soc Mass Spectrom. 2013 Apr;24(4):609-14. doi: 10.1007/s13361-012-0563-z. Epub 2013 Feb 9.
Targeted multiplex imaging mass spectrometry utilizes several different antigen-specific primary antibodies, each directly labeled with a unique photocleavable mass tag, to detect multiple antigens in a single tissue section. Each photocleavable mass tag bound to an antibody has a unique molecular weight and can be readily ionized by laser desorption ionization mass spectrometry. This article describes a mass spectrometry method that allows imaging of targeted single cells within tissue using transmission geometry laser desorption ionization mass spectrometry. Transmission geometry focuses the laser beam on the back side of the tissue placed on a glass slide, providing a 2 μm diameter laser spot irradiating the biological specimen. This matrix-free method enables simultaneous localization at the sub-cellular level of multiple antigens using specific tagged antibodies. We have used this technology to visualize the co-expression of synaptophysin and two major hormones peptides, insulin and somatostatin, in duplex assays in beta and delta cells contained in a human pancreatic islet.
靶向多重成像质谱技术利用几种不同的抗原特异性一抗，每种一抗都直接标记有独特的光解质量标签，以在单个组织切片中检测多种抗原。与抗体结合的每个光解质量标签都具有独特的分子量，可以通过激光解吸电离质谱法容易地进行离子化。本文描述了一种质谱方法，该方法允许使用透射几何结构的激光解吸电离质谱对组织内的靶向单细胞进行成像。透射几何结构将激光束聚焦在放置在载玻片上的组织的背面，提供直径为 2μm 的激光点，辐照生物标本。这种无基质的方法能够使用特异性标记的抗体同时在亚细胞水平上对多种抗原进行定位。我们已经使用该技术在人胰岛中β和δ细胞内的双检测中可视化突触素和两种主要激素肽（胰岛素和生长抑素）的共表达。
