Microirradiation of cells with energetic heavy ions
Microirradiation of cells with energetic heavy ions
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DOI：
10.1007/s00411-003-0222-7
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发表时间：
2004-02-01
影响因子：
1.7
通讯作者：
Dollinger, G
中科院分区：
文献类型：
--
作者：
Hauptner, A;Dietzel, S;Dollinger, G
慕尼黑14 MV串列加速器的离子微探针SNAKE通过超导四极偶实现束聚焦，并且可以利用从20 MeV质子到200 MeV金离子的宽范围的离子和离子能量。由于这些特性，SNAKE对于生物微束实验特别有吸引力。在这里，我们描述的适应蛇的细胞样品的微照射。这包括扩大的焦距，以调整焦平面的显微镜的样品台，建设的光束出射窗口在一个灵活的喷嘴和一个合适的细胞遏制，以及开发的程序在线聚焦的光束，制备单离子和扫描的静电偏转的光束。当用单个100 MeV O-16离子照射时，适应的设置允许在x方向上的0.91 μ m（半高全宽）和在y方向上的1.60 μ m的照射精度，如聚碳酸酯箔的回顾性轨道蚀刻所示。累积的修复蛋白Rad 51，通过免疫荧光检测，被用作生物跟踪检测器照射后的HeLa细胞与几何图案的计数离子。观察到的模式的荧光灶同意相当不错的照射模式，表明成功的适应蛇。尽管单离子照射，我们经常观察到分裂的荧光灶，这可能是由小规模的染色质运动。
The ion microprobe SNAKE at the Munich 14 MV tandem accelerator achieves beam focussing by a superconducting quadrupole doublet and can make use of a broad range of ions and ion energies, from 20 MeV protons to 200 MeV gold ions. Because of these properties, SNAKE is particularly attractive for biological microbeam experiments. Here we describe the adaptation of SNAKE for microirradiation of cell samples. This includes enlarging of the focal distance in order to adjust the focal plane to the specimen stage of a microscope, construction of a beam exit window in a flexible nozzle and of a suitable cell containment, as well as development of procedures for on-line focussing of the beam, preparation of single ions and scanning by electrostatic deflection of the beam. When irradiating with single 100 MeV O-16 ions, the adapted set-up permits an irradiation accuracy of 0.91 mum (full width at half maximum) in the x-direction and 1.60 mum in the y-direction, as demonstrated by retrospective track etching of polycarbonate foils. Accumulation of the repair protein Rad51, as detected by immunofluorescence, was used as a biological track detector after irradiation of HeLa cells with geometric patterns of counted ions. Observed patterns of fluorescence foci agreed reasonably well with irradiation patterns, indicating successful adaptation of SNAKE. In spite of single ion irradiation, we frequently observed split fluorescence foci which might be explained by small-scale chromatin movements.