By Michael Sherriff, Darren J. Bauer, Karen Salomon, Michael Afara, and Johnie Young; Thermo Fisher Scientific
Residual host cell DNA is a common process-related impurity that is typically co-monitored with host cell protein. We have previously reported on a quantitative PCR (qPCR) based assay for monitoring host cell proteins (A customizable, qPCR-based immunoassay platform for accurate quantitation of protein impurities and contaminants).
Here we report on high performance Host Cell Residual DNA extraction and quantitation using a streamlined and high throughput semi-automated workflow. Sample preparation and extraction is achieved in under two hours using a sample preparation kit based on antibody coated magnetic beads and a magnetic particle processing instrument. Sample quantitation is carried out on a real time PCR instrument. Recoveries of greater than 85% are obtained from a standard spiked solution with CV% less than 10% for Chinese Hamster Ovary (CHO) host cell DNA. Excellent linearity is observed for concentration ranges 3 pg/mL to 300,000 pg/mL of CHO residual DNA.