Large-Scale Culture and Plasmid Preparation Procedure for Low-Yield Bacmids Containing Full-Length SARS-CoV-2 cDNAs

Area of Science:

• Virology
• Molecular Biology
• Genetics

Background:

• Reverse genetics are essential for viral genome manipulation and phenotype analysis.
• SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) reverse genetics are challenging due to genome size and bacterial instability.
• Bacterial artificial chromosome plasmids (bacmids) are used but often difficult to amplify faithfully.

Purpose of the Study:

• To provide a detailed protocol for growing and amplifying SARS-CoV-2 bacmids.
• To address the challenges associated with maintaining the integrity of large, unstable viral genomes in bacteria.
• To optimize techniques for producing high-yield, mutation-free SARS-CoV-2 bacmids.

Main Methods:

• Utilizing low-copy number bacterial artificial chromosome plasmids (bacmids).
• Implementing a maxi-preparation procedure for large, unstable bacmids.
• Highlighting optimal techniques for bacterial culture and plasmid amplification.

Main Results:

• A detailed protocol for growing SARS-CoV-2 bacmids is presented.
• Challenges in amplifying SARS-CoV-2 bacmids are identified and addressed.
• Techniques for producing large quantities of mutation-free SARS-CoV-2 bacmids are optimized.

Conclusions:

• Successful amplification of stable SARS-CoV-2 bacmids is achievable with optimized protocols.
• This method facilitates downstream applications in SARS-CoV-2 research.
• The protocol aids in generating reliable reporter virus genomes and analyzing viral mutations.