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

通过在液氮中冷冻细菌细胞来固定细菌细胞，并且在丙酮和干冰的混合物中用丙酮代替水。将固定并脱水的细胞包埋在环氧树脂中并制成薄片。通过与常规化学固定法的比较，获得了以下新的细菌细胞形态学发现.革兰氏阴性菌的外膜光滑无波纹。周质间隙是一个充满电子致密物质的薄间隙.革兰氏阳性菌壁表面覆盖有一层绒毛或一层细纤维.被膜是一层由粗纤维组成的膜层。细菌类核是细胞质中缺乏核糖体的区域。实验结果表明，快速冷冻法是一种保存细菌结构的优良方法，能在接近于其生命状态的条件下保存细菌的结构。

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.