MOORE D H, MORGAN C, ROSE H M
J Biophys Biochem Cytol. 1956 Jul 25;2(4 Suppl):21-8. doi: 10.1083/jcb.2.4.21.
A technique for the examination of specimens at low electron beam intensity has been presented. Sections micrographed with this technique showed numerous knife scratches and frequently contained bands running parallel to the knife edge. Banding with an average spacing of 0.2 micro appeared to result from periodic distortion produced by impact of the knife. At the beam intensities customarily employed, differential sublimation and probably flow of the methacrylate resulted in obliteration of the bands and all but the deepest knife scratches. In addition, changes in the size, shape, and orientation of certain structures were noted. Artifacts resulting from incineration or sublimation of tissue components fixed in formalin were illustrated, and the suggestion was made that such instability to the electron beam accounted in part for the differences observed in osmium- and formalin-fixed tissues. The deformation revealed in serial sections was discussed, and it was pointed out that shortening in the axis perpendicular to the knife edge was associated with elongation in the axis parallel to the cutting edge, the elongation usually occurring locally without change in the width of the section. It was noted that the material causing contamination of the surface of sections during examination exhibited no structure but caused progressive loss of contrast.
本文介绍了一种在低电子束强度下检查标本的技术。用该技术拍摄的切片显微照片显示有许多刀痕，且常常含有与刀刃平行的条带。平均间距为0.2微米的条带似乎是由刀的撞击产生的周期性变形所致。在通常使用的电子束强度下，甲基丙烯酸酯的差异升华以及可能的流动导致条带和除最深刀痕外的所有痕迹消失。此外，还注意到某些结构的大小、形状和方向发生了变化。展示了用福尔马林固定的组织成分焚烧或升华产生的伪像，并提出这种对电子束的不稳定性部分解释了在锇固定和福尔马林固定组织中观察到的差异。讨论了连续切片中显示的变形，并指出垂直于刀刃轴的缩短与平行于切割边缘轴的伸长有关，伸长通常局部发生，切片宽度不变。注意到在检查过程中导致切片表面污染的物质没有显示出结构，但导致对比度逐渐降低。
