An effective method for isolation of DNA from pig faeces and comparison of five different methods

Area of Science:

• Microbiology
• Molecular Biology
• Biotechnology

Background:

• Polymerase chain reaction (PCR) detection of microorganisms in fecal samples is often limited by low DNA recovery and the presence of PCR inhibitors.
• Efficient extraction of high-quality microbial DNA is crucial for accurate molecular analysis of fecal communities.

Purpose of the Study:

• To develop and validate a modified method for extracting PCR-quality microbial community DNA from pig fecal samples.
• To improve DNA yield and purity compared to existing methods.

Main Methods:

• A novel DNA extraction protocol involving polyformaldehyde pretreatment, CTAB-based lysis with PVP and beta-mercaptoethanol, and chloroform-based purification (without phenol).
• Comparison of the modified method with four other widely used DNA extraction techniques.
• Assessment of DNA yield and quality using agarose gel electrophoresis and PCR amplification of 16S rDNA fragments.

Main Results:

• The modified method significantly increased DNA yield by 1.3- to 11-fold compared to other tested methods.
• Agarose gel electrophoresis and 16S rDNA PCR amplification confirmed the high quality of extracted DNA.
• The improved method demonstrated superior performance over the QIAamp DNA Stool Mini Kit.

Conclusions:

• The developed method is a reproducible, simple, and rapid technique for routine DNA extraction from fecal specimens.
• This improved protocol effectively overcomes challenges associated with low DNA yield and PCR inhibitors in fecal samples.
• The method provides high-quality DNA suitable for downstream molecular applications like PCR-based microbial detection.