Automated DNA sequencing methods involving polymerase chain reaction

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Polymerase chain reaction (PCR) is a widely used technique for DNA amplification.
• DNA sequencing is crucial for genetic analysis and understanding biological processes.
• Existing sequencing methods can be time-consuming and require extensive sample preparation.

Purpose of the Study:

• To develop a direct in situ sequencing method for PCR products.
• To improve the efficiency and accuracy of DNA sequencing.
• To enable automated analysis of complex genetic regions, such as the HLA-DQA-1 locus.

Main Methods:

• Utilized the dideoxy-termination method with fluorophore-labeled sequencing primers.
• Developed an in situ procedure for direct sequencing of PCR amplicons.
• Combined sequencing reactions for single-lane electrophoresis on a fluorescence-based DNA sequence analyzer.
• Employed a "PCR gene walking" strategy for sequencing unknown DNA fragments.

Main Results:

• Achieved over 99% accuracy in sequencing a 351-bp bacteriophage lambda genome region in a single lane.
• Successfully sequenced a 1.7 kb unknown DNA fragment with minimal ambiguities using PCR gene walking.
• Demonstrated unambiguous genotype assignment for the polymorphic HLA-DQA-1 locus from a blood sample.

Conclusions:

• The developed PCR-sequencing method offers a simple, accurate, and efficient approach for DNA template preparation and sequencing.
• This methodology facilitates automated DNA sequence analysis of complex and highly polymorphic genetic regions.
• The technique has significant implications for genetic research, diagnostics, and personalized medicine.