Preparation of G-Quartet Structures and Detection by Native Gel Electrophoresis

Mounting evidence supporting the existence of DNA structures containing G-quartets in vivo makes these unique and diverse nucleic acid structures an important research subject, and future investigations aimed at elucidating their biological significance are expected. The purification and characterization of G-quartet structures can be challenging because their inherent structural diversity, complexity, and stability are sensitive to an array of variables. The stability of G-quartet structures depends on many factors including number of DNA strands involved in G-quartet formation, the identity of the stabilizing cation(s), the number and sequence context of the guanosines involved in stacking, the presence of single-stranded overhangs, the intervening loop size, and the identity of nucleosides in the loop. Here we detail current methods used in G-quartet preparation and their purification and characterization by native gel electrophoresis.