The Interaction of Positively-charged Ions with Nucleic Acid Systems

The successful development of extremely low background sample cells for x-ray scattering studies has enabled experiments designed to elucidate some of the fundamental physical interactions involved in macromolecular folding. Microfabrication techniques were used to fabricate low volume (50 micro-liter) sample cells with silicon nitride membranes (sub micron in thickness) as x-ray windows. Scientifically, these studies focus on the interaction of negatively charged nucleic acid systems, RNA and DNA, with their surrounding (positively charged) ion atmospheres. Understanding the structure of the ion atmosphere and its influence on the shape/conformation of the macromolecule will help reveal the underlying physical forces employed by nature in the self-assembly of these important molecules.