A new method for DNA and RNA purification

While nucleic acid-based methodologies have become fully integrated into ba sic research laboratories, clinical laboratories have found much of the tec hnology difficult to utilize for rapid, routine diagnostic procedures. In p articular, current extraction protocols for DNA and RNA remain a cumbersome and time consuming obstacle to integrating molecular technology into the c linical laboratory. We describe a unique, rapid, and rigorous method for ob taining highly purified RNA and DNA from eukaryotic, bacterial, and viral s amples. The procedure incorporates: I) ionic detergent-based cellular disru ption, 2) salt precipitation of the proteins, and 3) precipitation of the n ucleic acids. Where desired, treatment with RNase-free DNase I eliminates D NA from RNA preparations, while treatment with RNase A provides DNA free of intact RNA. DNA or RNA can be purified in less than 60 minutes. This proce dure was used to extract nucleic acids from hepatitis C virus (HCV) positiv e human plasma, Saccharomyces cerevisiae, Staphylococcus aureus, a mouse ta il snip, tissue culture cells, and from human serum mock-infected with E. c oli. The nucleic acids obtained were free of contaminating protein as deter mined by UV spectrophotometry. The functional integrity of the extracted nu cleic acids was confirmed using polymerase chain reaction (PCR) of a tetran ucleotide repeat marker from human DNA and the gene encoding the 16S riboso mal RNA from E. coli. The quality of the RNA prepared using this method was assayed using reverse transcription-PCR (RT-PCR) to amplify HCV RNA from h uman serum samples. The nucleic acid purification protocol described here i s commercially available and provides research, clinical, forensic, and pha rmaceutical laboratories with a user friendly, non-hazardous method for ext racting DNA or RNA from a variety of sources.