Repetitive DNA occurs widely, if not universally, among higher organisms. A variety of procedures has been developed or adapted to examine its characteristics and a body of concepts and language has grown up to deal with its complexities. This chapter attempts to summarize this body of knowledge and technique. Owing to human frailty and the real problems of the subject, it tends to emphasize the approaches and conceptual position. The chapter describes techniques for the analysis of repeating DNA sequences by reassociation and a method for the evaluation of rate constants. The purity of the DNA's used in reassociation is critical, as the presence of contaminating proteins and metal ions can markedly alter reassociation results and reproducibility. Metal ions can be removed from DNA by passing it over Chelex 100 (Bio-Rad Labs) that has been neutralized and equilibrated with buffer.

© 1974 Academic Press. Much of this work was done at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, and the latter parts were done at the California Institute of Technology and were supported by U.S. Public Health Service Grant No. HD05753 and National Science Foundation Grant No. GB-33441x. D.E.G. was supported by a Damon Runyon Post-Doctoral Fellowship. B.R.N. was supported by the National Institute of Health. The realization of the hydroxyapatite technique for this purpose was the work of D. E. Kohne, and he has contributed at all levels to the study of renaturation kinetics and its implications.