We have developed the yttrium oxide (YNP) or ytterbium oxide (YbNP) nanoparticle/polymer matrices for the size-dependent separation of DNA ranging from 100 bp to 9,000 bp. High separation efficiency (> 10 6 plates/m) and the baseline resolution for various DNA standards (100 bp, 500 bp, and 1 kbp DNA ladder) were obtained in 10 min with these matrices. The effects of concentrations of both polyethylene oxide (PEO) and nanoparticles were investigated and the highest performance was obtained at 0.02% PEO with 0.02% YNP or YbNP. Similar sieving power for both YNP and YbNP matrices was observed probably due to the similar sizes of nanoparticles, resulting in the formation of comparable sieving networks for DNA separation. For the reduction of electrosmotic flow, either dynamic or permanent coating of the capillary inner wall was compared and it turned out that PEO was superior to polyvinylpyrrolidone (PVP) or polyacrylamide (PAA) for better separation efficiency.

Analysis of DNA has represented the deep insight of diagnostic and clinical information in individuals for detecting and treating genetic diseases related to loss of heterozygosity, mutation, gene copy number, and genotype. [1][2][3] Traditional DNA assays involve extraction of DNA from whole blood, amplification by the polymerase chain reaction, 4 and subsequent separation using slab gel electrophoresis.5 Although this process is known to be reasonably successful, it is generally time-consuming and unsuitable for high-throughput analysis.6 A smaller reaction volume would be beneficial to reduce the cost of reagents and the amount of waste generated. Extraction of DNA from cellular constituents is also a key for most nucleic acid-based drug discovery and clinical diagnostic applications.7 It is important that inhibitors or interfering substances from the cells and extracellular environment should be removed prior to PCR analysis. 8 Traditionally, the organic-based extraction and ethanol precipitation have been used to isolate and concentrate DNA prior to digestion and amplification. Although this procedure could handle about 10 to 20 μL of blood, it costs time and efforts due to many steps including cells lysis, several unltracentrifuges and precipitations.9,10 Commercial kits such as Qiagen DNA Stool Mini Kit and QIAamp DNA kit have provided relatively good extraction efficiency, however, drawbacks are increasing number of steps (more than 20 steps) for blood treatment and large sample volume (more than 250 μL). 11,12Several papers have been reported in order to overcome the disadvantages of the extraction of DNA from whole blood. For example, dendrimer-modified bacterial magnetic particles were employed based on the interaction of negatively-charged DNA and cations on dendrimer.13-15 This electrostatic interaction was also utilized on amino silane coated-polydimethylsiloxane (PDMS) microchip with the blood volume of less than 20 μL.15,16 Glass microchip with heat-treated frit was used for the extraction and detection of DNA from spores of the vaccine strain. Although somewhat effective extraction was achieved with magnetic particles or microchips, many shortcomings such as long modification time, intricate control of coating, and high cost for microchip production should be considered before the experiment. Recently, DNA purification process with adsorption of DNA onto a solid surface via hydrogen boding to silica and via electrostatic interactions has been developed. 17,18 This approach allows inhibiting species to be removed before the purified DNA is eluted from the surface and affords the opportunity for miniaturization.In this paper, a capillary-based DNA extraction tool was developed for the blood volume of less than 3 μL. Only 3 steps were required before PCR amplification of extracted DNA. Glutathione-S-transferase genes related to bladder and breast cancer was tested with our extraction tool. The conditions for frit formation by photopolymerization including the ratios of photoinitiators, the frit len...