抄録
1) The materials used were acid-fast bact. Kedrowsky, S. sendai phage Krh and S. glallinarum phage Zt strain. DNA was extracted in a native form according to Chargaff's (in bacterial DNA) and Cohen's (in viral DNA) method. The purified samples were confirmed to be DNA of high purity from the results of various physicochemical identification.
2) Electronmicroscop pictures of DNA demonstrate various figures; associated micellized-network or branching fibers, coiled fibrils, singly separated elementary fibers.
3) The diameter of DNA elementary fiber is between 20-25Å, and this figure coincides with the value estimated by Kahler and the theoretical value reported Watson and Crick.
4) DNA fibers of varying length have been confirmed projecting from the tail of phages through observation of the purified phage sample kept in a refrigerator for a long period or repeatedly frozen and thawed, and this confirms Pollard's schema showing the phage DNA coiled in the head of a phage and its liberation into the host bacteria through the tail during invasion of a host bacterium.
5) By electron-staining with AgNO3 and La(NO3)3 DNA fiber could be clearly observed without shadowing.
6) As a beginning in the biogenetic research of purified DNA, transformation experiment has been carried out, and the authors have succeeded in transforming white pigment producing bacteria Elly strain into a light yellow pigment producing strain by culturing the Elly strain in a medium containg in DNA obtained from yellow pigment producing Kedrowsky strain.
