Recent work in assembly of complex DNA nanostructures has demonstrated the effectiveness with which the non-covalent forces of DNA hybridization can drive formation of a topologically rich set of engineered DNA nanostructures. These DNA nanostructures can be used as structural components within a variety of complex nanosystems, including integrated systems for molecular detection. Successful design of strategies for integration will benefit from extensive characterization of the bulk samples as prepared. While thermodynamic characterization is executed most simply on bulk samples, structural characterization to date, largely has been limited to imaging of samples electrostatically adhered to a surface. While AFM images of DNA nanostructures on mica provide beautiful direct evidence of successful assembly, little is known about the selectivity of the adsorption process and the relationship between the distribution of products as prepared and the distribution observed on the surface. End point characterization methods such as AFM are limited, as well, by their inability to provide insight into the process of assembly. Clarification of the processes and products of DNA nanostructure self assembly will, thus, benefit from further characterization of the structures in solution. Here, we report structural and thermodynamic characterization of bulk samples of DNA nanostructures through a number of techniques not previously applied. UV extinction spectra, which report primarily on helix formation, and UV elastic scattering spectra, which report primarily on formation of the largest DNA assemblies, collected as a function of temperature provide complementary information on nanostructure thermodynamics. Dynamic light scattering, unimpeded electrophoretic mobility measurements, and small angle x-ray scattering provide information about the size, zeta potential, and three dimensional conformation and distribution of products in the solution phase ensembles. Solution phase structural results are compared to atomic force micrographs for the purpose of characterizing the effect of DNA assembly-substrate interactions on DNA assembly structure and deposition.