[Modified Giemsa technique for the study of characteristic chromosomes of leukemic C57Bl mice]

G-banded karyotypes have been studied in C57Bl control mice and in animals developing leukemia after i.p. injection of acellular extract of spleen or lymph nodes from isologous animals showing radiation induced leukemia. No visible differences could be detected with respect to the number, size and position of the G-bands between the two groups of animals. From the present observations and from previous work with conventional staining methods, it can be concluded that the development of such leukemia does not involve the presence of chromosome abnormalities.