[DNA assay for genetically engineered pharmaceutical substances using the real-time PCR technique]

Area of Science:

• Biotechnology
• Molecular Biology
• Pharmaceutical Analysis

Background:

• Ensuring the purity of biopharmaceuticals like human recombinant insulin is critical for patient safety.
• Residual host cell DNA, particularly from Escherichia coli (E. coli), must be rigorously monitored.
• Current methods may require improvement for sensitive and efficient detection of residual DNA.

Purpose of the Study:

• To develop and validate a real-time quantitative PCR (qPCR) assay for detecting E. coli residual DNA.
• To quantify both plasmid and genomic E. coli DNA in pharmaceutical intermediates and the final insulin product.
• To establish a reliable method for quality control in recombinant insulin production.

Main Methods:

• Development of a real-time PCR assay targeting specific E. coli DNA sequences.
• Amplification of fragments from the bla gene (plasmid DNA) and the 16S RNA gene (genomic DNA).
• Quantitative analysis of DNA using qPCR on samples from various stages of insulin purification and the finished product.

Main Results:

• The developed real-time PCR procedure effectively detected and quantified E. coli residual DNA.
• Both plasmid and genomic DNA from E. coli were successfully measured in process intermediates.
• Residual E. coli DNA levels were determined in the final human recombinant insulin product, confirming assay applicability.

Conclusions:

• Real-time PCR provides a sensitive and specific method for assaying E. coli residual DNA in human recombinant insulin.
• The assay is valuable for monitoring DNA contamination throughout the manufacturing process.
• This method contributes to ensuring the safety and quality of pharmaceutical products derived from recombinant DNA technology.