Cell substrate used in biologics production should be evaluated the genetic stability in both master cell bank (MCB) and end of production cell (EOPC) as described in regulatory guidelines, monitoring its genetic locus, coding sequence of the expression cassette or the RNA transcript, the copy number of the transgene. As well, restriction enzyme mapping is suggested to demonstrate integrity and integration pattern of transgene.
The genetic stability is recommended in WHO by comparing the profiles in both MCB/WCB and ECB/EOPC. The aspects such as the copy number of GOI (gene of interest), the location of GOI, and the sequences using sanger sequencing should be included.
Study Item | BRC Method |
---|---|
Purity |
GOI and Flanking Sequencing RT-qPCR |
Genomic Structure | Restriction enzyme analysis by Southern Blot |
Insert Gene Copy Number | qPCR |
Transcript Size | Northern blot |
Cell Line Identity | CO1 |
Karyotype | Karyology |
According to ICH 05B and WHO guidelines, it is required to compare the genetic stability between master cell banks (MCBs) and end-of-production cell lines (EOPCs), including the accuracy of coding DNA sequences, insertion site structure stability, and insertion copy number, etc.
Compared with traditional Southern Blotting, FISH and amplicon sequencing, TLA (Targeted Locus Amplification) next generation sequencing technology will bring a new solution for genetic characterization analysis.
BRC is the unique authorized domestic partner of Cergentis 1. Cergentis proprietary TLA-based assays offer clear advantages over standard approaches, most of which are unable to resolve all essential genetic characteristics in one experiment, e.g. as integration mutagenesis or sequence information. Briefly, genomic DNA is crosslinked, fragmented and circular DNA fragments are generated. The locus of interest is amplified and sequenced with NGS technology, and the sequence data are subsequently analyzed.
Characterization | TLA+NGS | WGS | Amplicon/Capture based | qPCR/ddPCR | Southern Blot | FISH | |
---|---|---|---|---|---|---|---|
Integration site | ✓ | — | — | × | x | ✓ | |
Structural variation | ✓ | × | — | × | × | × | |
Convergent integration | ✓ | × | × | × | × | × | |
Integrate a vector or GOl | SNVs | ✓ | — | ✓ | × | × | × |
Indels | ✓ | — | — | × | × | × | |
Rearrangement | ✓ | × | × | × | × | × | |
Tandem | ✓ | ✓ | × | × | × | × | |
Copy number | — | ✓ | — | ✓ | × | × |