Fabrication of Monolithic Silica Microchip for Efficient DNA Purification
Eman Alzahrani

Eman Alzahrani, Asst. Prof., Department of Chemistry, Faculty of Science, Taif University, 888-Taif, Kingdom of Saudi Arabia.
Manuscript received on December 10, 2014. | Revised Manuscript Received on December 12, 2014. | Manuscript published on December 18, 2014. | PP: 13-18 | Volume-2, Issue-1, December 2014.
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© The Authors. Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: The demand for high purity deoxyribonucleic acid (DNA) is still increasing. The aim of this work is to fabricate a microchip that has the ability to preconcentrate DNA from biological samples with a high extraction efficiency compared to commercial DNA extraction kits. This was achieved by fabrication of monolithic materials, followed by placing the monolithic silica disk inside the extraction chamber of the polycarbonate microchip. The formation of the mesopores on the silica skeleton was achieved by treating the monolithic silica rod, using different concentrations of aqueous ammonia solution, mainly 0M, 1M, 5M, and 7M, while all other parameters involved in the fabrication of the monolithic silica rods were kept identical. The fabricated materials were studied using EDAX analysis, TEM analysis, and the SEM analysis. Based on the results, 5 M ammonia solution was chosen for optimisation of fabrication of silica-based monolith. Moreover, the benefit of integrating solid-phase nucleic acid extraction techniques into a microfluidic system was to get highly efficient isolation of target analytes due to beneficial surface area characteristics. In this study, isolation of nucleic acids from mouse liver was achieved using a silica-based monolith, onto which nucleic acids were adsorbed onto a solid support; the residual biological matrix and any exogenous contaminants were then removed by washing the monolithic materials with 80% ethanol, and finally the purified DNA was eluted from the microchip using 200 µL of 10 mM tris-EDTA buffer solution (pH 8.5). The data showed that the UV absorption ratio of A260/A230 was 1.75±0.05 and the absorbance ratio of A260/A280 was 1.70±0.04 for the fabricated microchip, showing a good degree of purity. It would be interesting to investigate the use of the fabricated microchip for purification of DNA from forensic samples.
Keywords: Deoxyribonucleic acid (DNA); extraction method; monolithic materials; polycarbonate microchip; sol-gel method.