CAPILLARY ELECTROPHORETIC STUDY OF THE COMPLEX-FORMATION BETWEEN DNA AND CATIONIC SURFACTANTS

Due to the growing interest in the use of cationic surfactants for the construction of liposomal genetic delivery systems, the study of comp lex formation between DNA and quaternary ammonium detergents is of fun damental importance. In this context, we undertook the study of this c omplex formation using capillary zone electrophoresis (CZE) with suppr essed electroosmotic flow, a technique that allowed us to both monitor the change in mobility of DNA as a function of added surfactant in a precise and reproducible manner and evaluate the potential of CZE to r eflect the change in hydrodynamic friction upon binding. Nevertheless, CZE must be applied with caution for binding studies where strong coo perativity occurs, because of the presence of peak splitting at concen trations close to the half-point of binding. Also, a comparison betwee n this experiment and Manning's polyelectrolyte transport properties t heory on one hand and Tirade and Garcia de la Torre expression for hyd rodynamic friction of rod-like molecules on the other hand is given. ( C) 1998 Published by Elsevier Science B.V.