An improved filamentous helper phage for generating single-stranded plasmid DNA.

Area of Science:

• Molecular Biology
• Virology
• Biotechnology

Background:

• Gene cloning in filamentous phage vectors offers advantages but faces challenges.
• Low yields of single-stranded (ss) plasmid DNA and helper phage DNA contamination hinder procedures.
• Existing methods for producing ss plasmid DNA are often inefficient and problematic for sequencing.

Purpose of the Study:

• To develop a novel f1 helper phage to overcome technical difficulties in gene cloning.
• To improve the yield and purity of packaged single-stranded (ss) plasmid DNA.
• To reduce ambiguities in DNA sequencing caused by helper phage contamination.

Main Methods:

• Construction of a new f1 helper phage, designated R408.
• Utilizing R408 in small-scale procedures for gene cloning with plasmid vectors.
• Comparative analysis of ss DNA packaging and yield with the new phage versus existing methods.

Main Results:

• The new R408 helper phage preferentially packages and exports plasmid ss DNA over phage ss DNA.
• Absolute yields of packaged plasmid ss DNA are significantly increased using R408.
• Reduced contamination by helper phage ss DNA leads to clearer sequencing results.

Conclusions:

• The R408 helper phage represents a significant advancement for gene cloning using filamentous phage vectors.
• This new phage improves the efficiency and reliability of producing high-quality ss plasmid DNA.
• R408 facilitates more accurate DNA sequencing by minimizing helper phage-related artifacts.