Currently, there are several protocols to extract bacterial DNA based on different principles. However, the quantity and the quality of the DNA obtained by each method are highly variable and microorganism dependent. In most of these classical crude methods, highly toxic and hazardous organic solvents such as phenol and chloroform are used for deproteinization, whereas in certain protocols, expensive enzymes including RNases and Proteinases are used. This study was designed to introduce a simple, rapid, inexpensive and effective genomic DNA isolation procedure for Gram-negative bacteria, without the usage of toxic chemicals and costly enzymes. This novel method was compared with another classical method known as the salting-out method, which uses proteinase-K. Concentration and yield of the extracted DNA were determined by gel electrophoresis by comparing the gel band intensity of the sample DNA to that of a DNA quantitation standard and by the Quantus™ fluorometer. According to the results, the yield of extracted DNA was higher in the novel method compared to the salting-out method. Moreover, the entire process was accomplished in less than 2 h with the novel method. Purity and integrity of extracted genomic DNA by both methods were similar. In addition, the quality of DNA was determined using Multicopy Associated Filamentation (MAF) gene amplification by polymerase chain reaction (PCR). Thus, the described technique is non-toxic, less time and fund consuming, efficient and a well-suited method for routine DNA isolation from Gram negative bacteria.

目前，有多种基于不同原理的细菌 DNA 提取方案。然而，每种方法获得的 DNA 的数量和质量差异很大并且依赖于微生物。在大多数这些经典的粗方法中，使用苯酚和氯仿等剧毒且危险的有机溶剂进行脱蛋白，而在某些方案中，使用包括RNA酶和蛋白酶在内的昂贵的酶。本研究旨在介绍一种简单、快速、廉价且有效的革兰氏阴性细菌基因组 DNA 分离方法，无需使用有毒化学品和昂贵的酶。将这种新方法与另一种称为盐析法（使用蛋白酶-K）的经典方法进行了比较。通过凝胶电泳，将样品 DNA 的凝胶条带强度与 DNA 定量标准品的凝胶条带强度进行比较，并通过 Quantus™ 荧光计确定提取的 DNA 的浓度和产量。结果表明，与盐析法相比，新方法提取DNA的得率更高。此外，采用新方法，整个过程在不到2小时内完成。两种方法提取的基因组 DNA 的纯度和完整性相似。此外，通过聚合酶链式反应 (PCR) 进行多拷贝相关丝状 (MAF) 基因扩增来确定 DNA 的质量。因此，所描述的技术是无毒的、耗时和资金消耗少、高效且非常适合从革兰氏阴性细菌中常规分离DNA的方法。