Bacterial DNA Extraction Using Silica Gel: A New Method with High Quality and Simplicity

Background & Objectives: Today, major progress has been made in molecular experiments. The first step towards improving these experiments is the accurate extraction of nucleic acid. In this study, a protocol for DNA extraction was proposed in accordance with silica gel method. DNA purification, developed based on the silica-gel-membrane technology, is a simple method, which involves three stages of binding, rinsing, and recycling. Nucleic acids, unlike polysaccharides and proteins, are absorbed by silica gel in the presence of chaotropic agents and are removed through rinsing. Following the stage of rinsing, purified nucleic acids are extracted from silica gel through rinsing with buffer or distilled water. Accordingly, the aim of the present study was to introduce a simple, high-quality DNA extraction method. Materials and Methods: In this study, eight bacterial samples, including three Gram-positive and five Gram-negative bacteria, were evaluated. DNA extraction of all specimens was performed, using dissolved silica gel. Optical density was measured by a spectrophotometer. Moreover, the quality of the samples was assessed through Agarose gel electrophoresis. The mean absorbance at ۲۶۰/۲۸۰ nm was estimated at ۱.۹۲. Also, electrophoresis of PCR products was performed on ۱.۵% Agarose gel. Results: The mean DNA absorbance at ۲۶۰/۲۸۰ nm in Gram-negative and Grampositive DNAs, extracted from whole blood cells, was ۱ and ۱.۲۵, respectively. Based on the findings, Agarose gel electrophoresis of PCR products was shown to have good quality. Conclusion: According to the results of the present study, the proposed method showed higher efficacy for Gram-negative bacteria, compared to Gram-positive bacteria. Overall, gel silica method is recognized as a simple, cost-effective, and high-quality method. However, this method has several shortcomings, which can be resolved through increasing the assay time, improving the rinsing frequency, and altering the time of enzyme efficacy.

کلیدواژه ها:

Bacterial DNA extraction ، Silica gel ، سلیکا ژل ، استخراج DNA باکتریایی