Concentration of mammalian genomic DNA using two‐phase aqueous micellar systems

Abstract

The concentration of biomarkers, such as DNA, prior to a subsequent detection step may facilitate the early detection of cancer, which could significantly increase chances for survival. In this study, the partitioning behavior of mammalian genomic DNA fragments in a two-phase aqueous micellar system was investigated using both experiment and theory. The micellar system was generated using the nonionic surfactant Triton X-114 and phosphate-buffered saline (PBS). Partition coefficients were measured under a variety of conditions and compared with our theoretical predictions. With this comparison, we demonstrated that the partitioning behavior of DNA fragments in this system is primarily driven by repulsive, steric, excluded-volume interactions that operate between the micelles and the DNA fragments, but is limited by the entrainment of micelle-poor, DNA-rich domains in the macroscopic micelle-rich phase. Furthermore, the volume ratio, that is, the volume of the top, micelle-poor phase divided by that of the bottom, micelle-rich phase, was manipulated to concentrate DNA fragments in the top phase. Specifically, by decreasing the volume ratio from 1 to 1/10, we demonstrated proof-of-principle that the concentration of DNA fragments in the top phase could be increased two- to nine-fold in a predictive manner.

Interactions between DNA and Nonionic Ethylene Oxide Surfactants are Predominantly Repulsive

“…These findings are consistent with those previously obtained for samples containing DNA and 7.8 wt % Triton X-114 (which carries 9-10 EO units as its headgroup) in phosphate-buffered saline (PBS), 45 where the clear preference of DNA for the surfactant-poor phase was explained by repulsive, steric, excluded volume interactions.…”

Paper-Based Systems for Point-of-Care Biosensing

“…Specifically, when a volume ratio of 1:9 was used, the top phase (where the DNA wants to exist within) became 1/10 of the initial volume, and DNA became concentrated by approximately 10-fold in that phase. 29 In 2010, the Kamei group became the first to combine the technologies of ATPS and LFA. 30 Using the Triton X-114 micellar ATPS system and bacteriophage M13, they demonstrated that M13 was similarly concentrated by 10-fold into the top phase of a 1:9 volume ratio micellar ATPS.…”

Microfluidic extraction using two phase laminar flow for chemical and biological applications

“…Gomes et al used ATPS based on PEG 600, sodium citrate and ammonium sulfate were used to partially purify pDNA from Escherichia coli alkaline lysates to overcome the drawback that the wastewater streams generated in the polymer/salt TPS have high concentrations of phosphate or ammonium ions [22]. Mashayekhi et al investigated partitioning behavior of mammalian genomic DNA fragments in TPS with micellar system which was generated using the nonionic surfactant Triton X-114 and phosphate buffered saline (PBS) [23]. The integrated process for purification of pDNA using TPS combined with other procedures such as chromatography has been also investigated [19,24,25].…”