Synthetic oligonucleotides as quantitative PCR standards for quantifying microbial genes

Area of Science:

• Microbial Ecology
• Molecular Biology
• Environmental Science

Background:

• Real-time quantitative PCR (qPCR) is crucial for gene copy number quantification in microbial ecology.
• Traditional qPCR standard production involves tedious DNA cloning into plasmids.
• This bottleneck hinders the establishment of new qPCR assays.

Purpose of the Study:

• To develop and validate synthetic DNA fragments as efficient qPCR standards.
• To compare the performance of synthetic DNA standards against traditional plasmid standards.
• To assess the time and cost-efficiency of synthetic DNA standards.

Main Methods:

• Consensus sequences from 10-20 microbial genes were aligned to design synthetic DNA fragments.
• qPCR assays were performed using both synthetic DNA and plasmid standards.
• Assays targeted phylogenetic marker and functional genes in carbon (C) and nitrogen (N) cycling.
• Experiments utilized DNA extracted from diverse soil samples.

Main Results:

• qPCR standard curves generated using synthetic DNA performed comparably to those from plasmids.
• Gene copy numbers quantified using synthetic standards were consistent with plasmid standards.
• Synthetic DNA standards demonstrated equal sensitivity and reliability across tested genes and soil types.

Conclusions:

• Synthetic DNA fragments serve as effective qPCR standards, matching plasmid performance.
• This method significantly reduces the time and cost associated with qPCR assay development.
• The approach streamlines microbial gene quantification in ecological studies.