Radiation and Drug Induced Modification in the Adsorption Profile of DNA at Solid-Liquid Interface

Abstract

The present work involves the study of the adsorption profile of native, heat denatured, U. V. and gamma-irradiated DNA at an alumina-H₂O interface. Adsorption profile of proflavine and daunomycin complexed DNA has also been studied at H₂O alumina interface.

Adsorption occurred at positively charged surface of alumina. The quantity of gamma irradiated DNA on alumina was far more than the native and heat denatured samples and kinetic studies showed that gamma irradiated DNA was adsorbed much faster also. This property could be utilized for separation of the two forms over an alumina column.

The adsorption profile of U. V. irradiated DNA was similar to that of the native form whereas that of the heat denatured sample was similar to that of the gamma irradiated DNA.

In case of complexed DNA, proper experimental conditions were maintained to reduce intercalation considerably and to make the electrostatic binding predominant. Adsorption of drug-bound DNA was less than that of free DNA. The quantities of gamma-irradiated free and complexed DNA adsorbed were much greater than the corresponding unirradiated free and complexed DNA. There is positive cooperativity of gamma denatured DNA.