Doktycz M J, Sullivan C J, Hoyt P R, Pelletier D A, Wu S, Allison D P
Oak Ridge National Laboratory, Life Sciences Division, Oak Ridge, TN 37831-6123, USA.
Ultramicroscopy. 2003 Oct-Nov;97(1-4):209-16. doi: 10.1016/S0304-3991(03)00045-7.
Immobilization of particulates, especially biomolecules and cells, onto surfaces is critical for imaging with the atomic force microscope (AFM). In this paper, gelatin coated mica surfaces are shown to be suitable for immobilizing and imaging both gram positive, Staphylococcus aureus, and gram negative, Escherichia coli, bacteria in both air and liquid environments. Gelatin coated surfaces are shown to be superior to poly-L-lysine coated surfaces that are commonly used for the immobilization of cells. This cell immobilization technique is being developed primarily for live cell imaging of Rhodopseudomonas palustris. The genome of R. palustris has been sequenced and the organism is the target of intensive studies aimed at understanding genome function. Images of R. palustris grown both aerobically and anaerobically in liquid media are presented. Images in liquid media show the bacteria is rod shaped and smooth while images in air show marked irregularity and folding of the surface. Significant differences in the vertical dimension are also apparent with the height of the bacteria in liquid being substantially greater than images taken in air. In air immobilized bacterial flagella are clearly seen while in liquid this structure is not visible. Additionally, significant morphological differences are observed that depend on the method of bacterial growth.
将颗粒，尤其是生物分子和细胞固定在表面上，对于用原子力显微镜（AFM）成像至关重要。在本文中，明胶包被的云母表面被证明适用于在空气和液体环境中固定和成像革兰氏阳性菌金黄色葡萄球菌和革兰氏阴性菌大肠杆菌。明胶包被的表面被证明优于常用于固定细胞的聚-L-赖氨酸包被的表面。这种细胞固定技术主要是为了对沼泽红假单胞菌进行活细胞成像而开发的。沼泽红假单胞菌的基因组已被测序，该生物体是旨在理解基因组功能的深入研究的目标。展示了在液体培养基中好氧和厌氧生长的沼泽红假单胞菌的图像。液体培养基中的图像显示细菌呈杆状且表面光滑，而空气中的图像显示表面有明显的不规则和折叠。垂直尺寸也存在显著差异，液体中细菌的高度明显大于空气中拍摄的图像。在空气中可以清楚地看到固定的细菌鞭毛，而在液体中则看不到这种结构。此外，观察到显著的形态差异，这取决于细菌的生长方式。
