Examination of the Bacterial Ultrastructures by the Rapid Freezing and Substitution Fixation Technique.

将细菌细胞冷冻在液氮中固定，并在丙酮和干冰的混合物中用丙酮代替水。将固定脱水的细胞包埋在环氧树脂中，制成薄片。通过与常规化学固定的结果比较，在细菌细胞上获得了以下新的形态学发现。革兰氏阴性菌外膜光滑无波浪形。质周空间被看作是一个充满电子密集物质的薄空间。革兰氏阳性菌的细胞壁表面覆盖一层绒毛或一层细纤维。胶囊被看作是由厚纤维组成的一层。细菌的类核是细胞质中没有核糖体的区域。没有看到许多教科书中所描述的充满DNA纤维的结构。这些结果表明，快速冷冻方法是一种很好的技术，可以在非常接近其生活状态的条件下保存细菌结构。

The bacterial cell was fixed by freezing it in liquid nitrogen and the water was substituted with acetone in the mixture of acetone and dry ice. Thus fixed and dehydrated cell was embedded in epoxy resin and thin sections were made. In comparing the results with that obtained by the conventional chemical fixation the folowing new morphological findings on the bacterial cells were obtained.1. The outer membrane of the Gram-negative bacteria showed a smooth non-wavy appearence. The periplasmic space was seen as a thin space filled with electron dense materiales.2. The wall surface of the Gram-positive bacteria was covered with a layer of a fuzzy coat or a layer of fine fibers.3. The capsule was seen as a layer consisting of thick fibers.4. The bacterial nucleoid was seen as an area devoid of ribosomes in the cytoplasm. No structures filled with the fibers of DNA as presented in many of the text books was seen.These results indicated that the method of the rapid-freezing was an excellent technigue to preserve the bacterial structures in the conditions very close to their living state.