Lysosomal Diseases Research Unit, SA Pathology at Women's and Children's Hospital, 72 King William Road, North Adelaide, South Australia, Australia, 5006.
Anal Chem. 2010 May 1;82(9):3664-70. doi: 10.1021/ac902939k.
MALDI mass spectrometric imaging (MSI) enables spatially resolved mass and intensity information to be obtained directly from tissue sections, thereby illustrating how analytes are distributed within these sections. Here we have used an oversampling technique on a commercially available MALDI orthogonal acceleration TOF mass spectrometer with ion mobility separation capability to produce high spatial resolution images of the glycosphingolipid, glucosylceramide (GC). To exemplify the biological application of our approach, GC was imaged in spleen sections from a conditional knockout mouse model of type 1 Gaucher disease in which the catabolism of this glycosphingolipid is impaired. The laser was continually fired at one position until no more ions were observed and then the sample was moved by 15 microm (laser diameter approximately 150 microm). Ions were generated from only the unirradiated surface at each of these positions achieving an effective spacing of 15 microm. At 15 microm laser step-size, it was possible to visualize macrophages enriched in GC, which could be distinguished from other cell types in the spleen. Current MALDI MSI spatial resolution is typically limited by the diameter of the laser spot-size, which is usually between 50 and 100 microm, covering an area equivalent to tens of mammalian cells.
基质辅助激光解吸电离飞行时间质谱成像（MALDI MSI）能够直接从组织切片中获得空间分辨的质量和强度信息，从而说明分析物在这些切片中的分布情况。在这里，我们在具有离子淌度分离能力的商用 MALDI 正交加速飞行时间质谱仪上使用了过采样技术，以产生高空间分辨率的糖鞘脂，葡萄糖脑苷脂（GC）图像。为了举例说明我们方法的生物学应用，我们对 1 型 Gaucher 病的条件性敲除小鼠模型的脾脏切片中的 GC 进行了成像，在这种模型中，这种糖鞘脂的分解代谢受到了损害。激光持续在一个位置发射，直到不再观察到离子，然后将样品移动 15 微米（激光直径约 150 微米）。在这些位置的每个位置，仅从未辐照的表面产生离子，从而实现了 15 微米的有效间距。在 15 微米的激光步长下，可以可视化富含 GC 的巨噬细胞，这些巨噬细胞可以与脾脏中的其他细胞类型区分开来。目前 MALDI MSI 的空间分辨率通常受到激光光斑直径的限制，通常在 50 到 100 微米之间，覆盖相当于数十个哺乳动物细胞的区域。
