Chromosome Studies in Normal and Leukemic Rats

1. Adequate chromosome preparations were obtained in 70 per cent of normal rat peripheral blood cell cultures. However, cultures of peripheral blood cells from leukemic rats were almost universally unsuccessful.

2. In x-ray- and 3MCA-induced leukemias direct bone marrow preparations provided adequate metaphases in eight of 12 cases. Failures were attributed in four cases to scanty material obtained from fibrotic marrows.

3. No consistent chromosome abnormalities, such as those reported in human myelogenous leukemia, were found in these leukemic rats. However, the series of cases is small, and species differences and other factors may have influenced the results of these studies.