Extension and modification of Kanai's DNA isolation method for a spectrum of human specimens collected by invasive and noninvasive methods suitable for genotyping studies

Abstract

There are a number of conventional methods and kits available for human genomic DNA isolation. These methods however come with limitations such as high cost, time-consuming, hazardous, and complex steps. We propose an extended and modified kanai's method that can be used for DNA isolation from various human specimens (blood, clot, saliva, urine, and cell lines) and from Gram-negative bacterial samples. The DNA isolated by this method was tested for suitability in genetic analysis techniques such as PCR RFLP, ARMS PCR, and High Resolution Melt analysis. The DNA isolated had high purity (mean A260/A280 = 1.7 to 1.8) and was stable at 4°C and - 20°C. This method is suitable for very low volume of blood (20 μl), long stored blood (3 years), and also for noninvasive samples. The DNA gave consistent and accurate results in PCR RFLP, ARMS, and HRM techniques. We have demonstrated that the DNA isolation method is an effective method for fresh blood, blood clot, saliva, urine and cell line samples and we prove its applicability in genotyping studies.