Detection of mutations and polymorphisms using fluorescence-based dideoxy fingerprinting (F-ddF)

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• DNA sequence variants are crucial for understanding genetic diseases and traits.
• Existing methods for variant detection have limitations in precision and information provided.
• Fluorescence-detected single-strand conformation polymorphism analysis (F-SSCP) is a common technique.

Purpose of the Study:

• To adapt the dideoxy fingerprinting (ddF) technique for DNA sequence variant detection using fluorescence detection (F-ddF).
• To compare the efficiency and advantages of F-ddF against F-SSCP.
• To describe a strategy for utilizing F-ddF to overcome F-SSCP limitations.

Main Methods:

• Adaptation of the dideoxy fingerprinting (ddF) technique for fluorescence detection (F-ddF).
• Utilized an Applied Biosystems Model 373A DNA Sequencer with GENESCAN 672 software and external temperature control.
• Employed an internal standard for precise alignment of fingerprints and characterization of mobility shifts.

Main Results:

• F-ddF demonstrated equal efficiency to F-SSCP in detecting DNA sequence variants.
• F-ddF provides additional advantages including precise location of variations and improved reliability in distinguishing variants.
• The technique allows for the generation of large PCR fragments analyzed in smaller segments.
• Read length and data quality are sequence-dependent with Taq DNA polymerase, but can be improved by reducing terminator concentration.

Conclusions:

• F-ddF is a valuable alternative and complement to F-SSCP for DNA sequence variant detection.
• The method offers enhanced information regarding variant location and improved discrimination.
• F-ddF presents distinct strengths and weaknesses compared to F-SSCP, making it suitable for specific applications.