Comparison of the nucleic acid contents in various tissues of mice: Lymph nodes and thymus of non-leukemic and leukemic Ak mice, and livers of normal C3H mice

Abstract

1. 1. The concentration of the DNA was not altered significantly in the malignant cells (lymph nodal and thymic) of either the spontaneous or transmitted leukemic variety as compared to the corresponding cells of non-leukemic Ak mice. 2. 2. There is significantly more PNA in the thymic cells of the spontaneous and transmitted leukemic Ak mice than there is in the corresponding cells of the non-leukemic Ak mice. 3. 3. In the spontaneous leukemic Ak group, the PNA values are greater for the thymic cells than they are for the nodal cells, while the DNA concentrations did not vary in the cells of the corresponding tissues. 4. 4. In the non-leukemic and the transmitted leukemic Ak groups, the PNA content of the lymph nodal cells is greater than that of the thymic cells, while the DNA concentrations did not vary in the cells of the corresponding tissues. 5. 5. When cell fragments are being prepared by centrifugal fractionation for a study of the distribution of nucleic acids (such as the studies of Schneider [11,12]), the investigator must be absolutely positive that there is no enzymatic hydrolysis or degradation of the nucleoprotein before it is extracted. Otherwise, the quantity and distribution can not be considered as representative. 6. 6. The reproducibility of the extraction procedure used in this paper is extremely good (92–98 per cent). However, when the perchloric acid extraction procedure is used, all of the so-called “washes” must be monitored for pentose activity.