The sedimentation characteristics of deoxyribonucleic acid from human tissues

Abstract

Distribution curves of sedimentation coefficients at a concentra-tion 0.001-0.0015% have been determined for a group of preparations of deoxyribonucleic acid from normal and diseased human tissues and cells. Preparations from normal sources gave average sedimenta-tion coefficients of 25-27s; all preparations from leukocytes of lympha-tic leukaemia were found to have higher than normal sedimentation coefficients, whereas in preparations from leukocytes of myeloid leukaemia the results were the same as, or less than, normal. Sedimen-tation coefficients lower than normal have been observed with prep-arations from spleens associated with Banti''s disease. Eight of the preparations have been analysed to determine the amount and composi-tion of the residual protein. There appears to be no correlation between these results and the source of the preparation of deoxyribonucleic acid or its sedimentation characteristics. The variation in sedimenta-tion behavior observed between different samples does not appear to be due to the presence of varying amounts of protein cross-linked aggregates, since treatment with any of the enzymes trypsin, chymo-trypsin, ficin or papain has no detectable effect.