Received on April 16, 2004
Accepted on July 9, 2004

Molecular Diagnostics and Genetics

Single-Tube Method for Nucleic Acid Extraction, Amplification, Purification, and Sequencing

¹ ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT
² Department of Pathology, University of Utah Medical School, Salt Lake City, UT

^* To whom correspondence should be addressed. E-mail: 18298{at}aruplab.com.

Background: The hepatitis C virus (HCV) genotype determines patient prognosis and duration of treatment, but sequencing of the gene is lengthy and labor-intensive. We used a commercially available nucleic acid extraction system to develop a single-tube extraction-to-sequencing (STETS) method for HCV genotyping.

Methods: HCV RNA was purified and amplified in tubes coated with a solid-phase matrix that irreversibly bound nucleic acid during the extraction step. After reverse transcription-PCR, the amplicon was adsorbed to the original extraction matrix for purification and use in the subsequent sequencing reactions.

Results: The STETS method generated genotyping-quality sequence for a range of HCV titers from 500 to 6 000 000 IU/mL. If a viral sample was detected during real-time reverse transcription-PCR, it could be sequenced and genotyped. Read lengths >600 bases were observed with the STETS method. Mixed infections were detected and genotyped if at least 15% of the minor species was present. Combining the STETS method with consecutive sequencing provided a means of performing both forward and reverse sequencing in a single tube.

Conclusions: A single-tube nucleic acid extraction-to-sequencing method. which requires less time and labor than conventional methods, generates HCV sequence data that are equivalent to conventional methods and can be used to genotype HCV.