Direct quantitative detection of host cell residual DNA in recombinant Filgrastim by qPCR.

Host cell residual DNA is considered as an impurity in recombinant biopharmaceuticals. This study aimed to develop a direct qPCR method to quantify E. Coli residual DNA in recombinant Filgrastim. The specific primers were designed to amplify E. Coli's 16S-rDNA genomic region, which encodes the 16S-rRNA. The developed qPCR method showed that the designed primer has specifically amplified the target genome without any secondary reaction. The designed primer was also able to amplify the target gene as a representative of residual DNA in the drug matrix. Results show that the amount of residual DNA in Filgrastim is undetectable.