Kellenberger E, Ryter A & Séchaud J. Electron microscope study of DNA-containing plasms. II. Vegetative and mature phage DNA as compared with normal bacterial nucleoids in different physiological states. J. Biophys. Biochem. Cytol. 4:671-8, 1958

Under specific conditions—later called the 'R.K.-conditions'—bacterial nucleoids can be fixed with OsO4 so as to contain fine fibrillar material when viewed on thin sections. Under other conditions, and —as was shown later —with aldehydes, aggregations occur. Those induced with EDTA (formerly under the trade name 'versene'} allow a practical aggregation test. The pool of vegetative ( = replicating and transcribing) T4 bacteriophage DNA is shown to be aggregation sensitive, as is the normal nucleoid. Artificial aggregation is different from physiological condensation as occurs, e.g., when T4-virions are packaged out of the DNA-pool. [The SCI indicates that this paper has been cited over 915 times since 1961.]