Due to the low packing density of C-star frameworks, self-assembly does not require the high cation concentration or divalent ions needed for compact DNA crystals and origami. When not stated otherwise, all experiments were performed with a sodium concentration of 300 mM and no divalent ions. In Fig. we show that crystallization is robust even at lower monovalent salt concentration, with well defined single crystals observed in 200 mM, 100 mM NaCl, and in physiological phosphate buffered saline (PBS). In all cases, SAXS demonstrates unchanged crystal symmetry and scattering resolution compared with samples prepared in 300 mM NaCl. Besides the BCC phase with lattice parameter identical to the one found in higher ionic-strength conditions, when reducing sodium concentration we observe the emergence of a secondary BCC phase with slightly expanded lattice parameter. We hypothesize that the secondary phase may appear due to conformational changes of the nanostar junction following reduced electrostatic screening. The robustness of C-star self-assembly also relaxes the strict need for using highly purified DNA oligonucleotides, which is standard in most DNA nanotechnology preparations. All but the cholesterol functionalized oligonucleotides in our experiments are purified (by the manufacturer) via conventional desalting, significantly reducing costs compared to purification steps based on High-Performance Liquid Chromatography or Polyacrylamide Gel Electrophoresis.