Arc-synthesized single-walled carbon nanotubes have been purified through preparative electrophoresis in agarose gel and glass bead matrixes. Two major impurities were isolated: fluorescent carbon and short tubular carbon. Analysis of these two classes of impurities was done. The methods described may be readily extended to the separation of other water-soluble nanoparticles. The separated fluorescent carbon and short tubule carbon species promise to be interesting nanomaterials in their own right.

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Circulating, cell-free DNA (ccfDNA) has emerged as an important tool in molecular oncology research. Because it is highly fragmented, present in small quantities, and highly susceptible to degradation, purification of ccfDNA poses unique challenges to researchers. While plasma is the main focus of many researchers for ccfDNA, recent work has shown that it is present in other biological fluids. Promega has developed a unique chemistry to selectively purify ccfDNA from plasma. The Maxwell RSC ccfDNA Plasma system is a completely automated system that allows purification of ccfDNA from 1ml of plasma. To add flexibility, we adapted the chemistry to automated platforms in 24-well configurations. These platforms include the Hamilton Microlab STAR series and the KingFisher Flex Processor. Because the biomarkers in ccfDNA can be of very low frequency, many researchers prefer to process volumes of samples >1ml which can exceed the capacity of many purification systems. Using a sequential bind strategy, we demonstrate that ccf DNA can be purified from at least 8ml sample draw using a fully automated method. Liquid draws tested include plasma and urine. DNA quantity was assessed by qPCR using an autosomal target, and quality was assessed using an internal PCR control. This study shows the flexibility and robustness of the Maxwell RSC ccfDNA chemistry. We successfully adapted it for purification from relatively large volume liquids in a fully automated manner making this a convenient option for early biomarker research. Citation Format: Robert Ray, Mark Bratz, Doug Wieczorek, Douglas White, Douglas Horejsh, Eric Vincent, Trista Schagat. Automated circulating cell-free DNA purification from large volume draws. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 492.