Abstract
Two-dimensional DNA lattices are grown under conditions that also are suitable for the magnesium-free growth of three-dimensional calcium carbonate crystals. These lattices are used to template morphology changes in calcium carbonate. The effects of DNA lattices, sub-assemblies, duplexes, single strands, dinucleotides, and mononucleotides on calcium carbonate morphology are studied. A "rotated" morphology of calcite is found to predominate when a critical concentration of any polynucleotide is reached in the templating solution.