Measurement of the molecular weight distributions in human muscular deoxyribonucleic acid

Highly purified DNA has been prepared from human muscle tissue and treated with three different single-strand specific desoxyribonucleases. The molecular weight of treated individual DNA molecules was determined by length measurements. Average DNA molecular weights and their standard deviations were correlated to the age of donors. No significant correlation could be established using seven different mathematical functions. Factor analytical considerations suggested grouping according to extreme smoking habits. Two populations with significant double linear correlations of age versus molecular weight and standard deviation then emerge. From the data it may be speculated that in heavy smokers with increasing age (or time of smoking) high molecular weight DNA integrity is lost to an increasing extent in post-mitotic tissue.