Sullivan C J, Morrell J L, Allison D P, Doktycz M J
Genome Science and Technology, The University of Tennessee, Knoxville, TN 37932, USA.
Ultramicroscopy. 2005 Nov;105(1-4):96-102. doi: 10.1016/j.ultramic.2005.06.023. Epub 2005 Jul 13.
The cytoplasmic membrane of Escherichia coli (E. coli) is the location of numerous, chemically specific transporters and recognition elements. Investigation of this membrane in vivo by atomic force microscopy (AFM) requires removal of the cell wall and stable immobilization of the spheroplast. AFM images demonstrate that spheroplasts can be secured with warm gelatin applied to the mica substrate just before the addition of a spheroplast suspension. The resulting preparation can be repeatedly imaged by AFM over the course of several hours. Confocal fluorescence imaging confirms the association of the spheroplasts with the gelatin layer. Gelatin molecules are known to reorder into a network after heating. Entrapment within this gelatin network is believed to be responsible for the immobilization of spheroplasts on mica.
大肠杆菌（E. coli）的细胞质膜是众多具有化学特异性的转运蛋白和识别元件的所在位置。通过原子力显微镜（AFM）对这种膜进行体内研究需要去除细胞壁并稳定固定原生质球。AFM图像表明，在添加原生质球悬浮液之前，将温热的明胶涂覆在云母基底上即可固定原生质球。所得制剂可以在数小时内通过AFM反复成像。共聚焦荧光成像证实了原生质球与明胶层的结合。已知明胶分子在加热后会重新排列成网络状。据信被困在这种明胶网络中是原生质球固定在云母上的原因。
