Morrison G H, Gay I, Chandra S
Baker Laboratory of Chemistry, Cornell University, Ithaca, NY 14853, USA.
Scanning Microsc Suppl. 1994;8:359-70.
Ion microscopy, a mass spectrometry based isotopic imaging technique, is uniquely suited for ion transport related problems in biological systems. Due to its high sensitivity, it can image the transport and distribution of both major and minor elements (isotopes) at subcellular resolutions. The images of major elements such as K, Na, CI, etc., can be viewed directly and recorded in real-time from the microchannel plate-fluorescent screen detector of the instrument. The low concentration physiologically important elements, such as Ca, need about one minute of integration for good quality imaging. The isotopic imaging capability of ion microscopy provides a unique approach for the use of stable isotopes as tracers. In this way, one can image both the endogenous and the transported isotopes independently. Strict cryogenic sample preparations are essential for ion transport studies. Correlative imaging of the same cell with laser scanning confocal microscopy and ion microscopy can positively identify smaller cytoplasmic compartments such as the Golgi apparatus in calcium images. We have identified the Golgi apparatus as a calcium storing organelle. Another unique application of ion microscopy is the imaging of boron from boronated drugs used in Boron Neutron Capture Therapy (BNCT) of cancer. Ion microscopy is capable of rapid screening of potential drugs for BNCT. This critical information is essential for the fundamental understanding of BNCT. Ion microscopy is now at the stage where it can provide previously unattainable answers to important biomedical questions.
离子显微镜是一种基于质谱的同位素成像技术，特别适用于生物系统中与离子运输相关的问题。由于其高灵敏度，它能够在亚细胞分辨率下对主要和次要元素（同位素）的运输和分布进行成像。钾、钠、氯等主要元素的图像可以直接从仪器的微通道板-荧光屏探测器实时观察和记录。钙等生理上重要的低浓度元素，高质量成像大约需要一分钟的积分时间。离子显微镜的同位素成像能力为使用稳定同位素作为示踪剂提供了一种独特的方法。通过这种方式，可以独立地对内源性同位素和运输的同位素进行成像。严格的低温样品制备对于离子运输研究至关重要。用激光扫描共聚焦显微镜和离子显微镜对同一细胞进行相关成像，可以在钙图像中明确识别较小的细胞质区室，如高尔基体。我们已将高尔基体鉴定为一种钙储存细胞器。离子显微镜的另一个独特应用是对用于癌症硼中子俘获疗法（BNCT）的硼化药物中的硼进行成像。离子显微镜能够快速筛选BNCT的潜在药物。这一关键信息对于从根本上理解BNCT至关重要。离子显微镜目前正处于能够为重要的生物医学问题提供以前无法获得的答案的阶段。
