Hospital of The Rockefeller Institute for Medical Research.
J Exp Med. 1938 Feb 28;67(3):389-98. doi: 10.1084/jem.67.3.389.
When used in low concentration, formaldehyde increases the rate of autolytic disintegration of pneumococci whereas in large concentrations it completely inhibits autolysis and preserves both the morphological and staining characteristics of the cells. Pneumococci treated with large concentrations of formaldehyde, then washed free of the antiseptic and resuspended in physiological solutions, rapidly undergo a change which renders them Gram-negative and smaller. The lysis is only partial, however, and is not accompanied by an actual disintegration of the cell. It is caused by the autolytic enzyme of the cell which remains inactive in the presence of an excess of formaldehyde but recovers its activity when the cells are resuspended in a neutral medium after removal of the antiseptic. If the autolytic enzyme is irreversibly inactivated by heating, or maintained inactive in acid or alkaline reaction, the formolized cells retain their staining characteristics and morphological integrity. Formolized pneumococci which have become Gram-negative owing to the action of their autolytic enzyme, fail to elicit the type specific carbohydrate antibodies in rabbits. Formolized pneumococci in which the autolytic enzyme has been destroyed or maintained inactive, and which have retained their Gram-positive character, function as a very effective type specific antigen in the rabbit. These observations emphasize once more the close relation between the Gram-positive structure of pneumococci and the capsular polysaccharide antigen of the cell. They can be used as a basis for the preparation of suspensions of formolized pneumococci which are stable and very effective as type specific antigens.
当甲醛被用于低浓度时，会增加肺炎球菌自溶分解的速度，而在高浓度时，它会完全抑制自溶，并保持细胞的形态和染色特征。用高浓度甲醛处理的肺炎球菌，然后用消毒剂冲洗干净并悬浮在生理溶液中，会迅速发生变化，使其变为革兰氏阴性且体积变小。然而，这种裂解是不完全的，细胞并没有真正解体。它是由细胞自身的溶酶体酶引起的，在甲醛过量的情况下，该酶保持不活跃，但在消毒剂去除后，细胞重新悬浮在中性介质中时，其活性会恢复。如果自身的溶酶体酶被加热不可逆地失活，或者在酸性或碱性反应中保持失活状态，那么甲醛固定的肺炎球菌仍然保留其染色特征和形态完整性。由于自身溶酶体酶的作用而变为革兰氏阴性的甲醛固定肺炎球菌，无法在兔子中引发特定类型的碳水化合物抗体。甲醛固定的肺炎球菌，如果自身的溶酶体酶被破坏或保持失活，并且保持革兰氏阳性特征，则在兔子中作为非常有效的特定类型的抗原发挥作用。这些观察结果再次强调了肺炎球菌的革兰氏阳性结构与细胞荚膜多糖抗原之间的密切关系。它们可以作为制备甲醛固定肺炎球菌悬浮液的基础，这些悬浮液稳定且作为特定类型的抗原非常有效。
