Vergleichende Elektronenmikroskopie reiner DNS und der DNS des Bakteriennukleoids

Summary The behaviour of pure isolated DNA towards the conditions of fixation and dehydration—prior to ultrathin sectioning—has been studied and compared with the behaviour of the DNA-plasm of the bacterial nucleus. It is found that those conditions which produce coarse coagulation of the free DNA also produce electron opaque bodies of variable aspect inside the bacterial nucleus. The coagulation figures obtained in both situations are very similar. This is a further direct evidence in favour of the view that the bacterial nucleus is an assembly of fine DNA-containing fibrilla in a highly hydrated plasma.