Comparison of the Nucleic Acid, Total Nitrogen, and Protein Nitrogen Levels of Normal and Tumor Tissue under Similar Growth Conditions.

Abstract

Crown gall and normal tissue of Parthenocissus tricuspidata were grown in culture in the presence of 7-azaindole propionic acid. Nucleic acid determinations were made by P analysis, and by spectrophotometric analysis. N was determined by micro-Kjeldahl methods. On a per-cell basis, the tumor tissue has about twice as much protein and nucleic acid as the normal. Slowing of the growth rate causes slight increases in the level of nucleic acid and protein, but relative differences between the 2 types of tissue are maintained. The difference in the DNA content of the 2 tissues and the alteration of DNA content resulting from the change in growth rate is not a result of changes in the chromosome number. All cells are apparently diploid. These data suggest the possibility of an increase in the amount of non-chromosomal DNA.