Identification and separation of components of calf thymus DNA using a CsCl-netropsin density gradient

Open Access
Publisher Website
Google Scholar
Abstract
Calf thymus DNA containing satellite components of various densities was used as a model to study the effect of netropsin on the density of DNA in a CsCl gradient. The binding of netropsin resulted in a decrease in density which depended upon the quantity of netropsin added and on the average composition of the DNA. Differences in density of DNA components were higher in CsCl - netropsin gradients than in simple CsCl gradients. By use of netropsin a main band and four satellite bands could be differentiated m calf thymus DNA. Satellite DNA's were isolated using preparative CsCl - netropsin gradient centrifugation and were characterised by density and homogeneity m native and in reassociated state. Two of the satellite conponents, with densities of 1.722 and 1.714 g/cm3, are probably of homogenous sequence, the other two components of densities 1.709 and 1.705 g/cm3 appear to be heterogeneous.