Southern Blot Services
The FDA requires confirmation of the genetic stability throughout the production process (MCB, WCB, EOPC) and that no clonal rearrangement has occurred within the integrated cell banks used to manufacture biotherapeutics. By providing information on the presence, copy number, and integration sites of transgenes, Southern blot analysis helps in confirming that cell banks are free from unwanted genetic alterations or contamination, which is critical for maintaining consistency and efficacy in drug production.
Our Expertise
Avance Biosciences team has a long history of providing Southern blot analysis to support cell bank characterization for protein therapeutics development and manufacturing. Radioactive (P32) labeled hybridization probes are used in our lab for blotting and a Typhon FLA 7000 phosphorimager is used for detection. The quality of our blots is second to none, especially when considering most of our blots are done without the need of optimization.
Southern Blot Applications:
Application
Description
Integration Site and Structural Change Analysis
Southern Blotting is used to evaluate gene integration sites and to confirm the structure of the integrated gene.
Integrated Cell Clone Selection
Various integrated cell clones are evaluated with multiple probes to select clones with the desired integrations.
Single Clone Confirmation
We can perform limited dilution cloning of a cell bank followed by Southern blot analysis to determine whether the cell bank is comprised of a single clone.
Gene Knock-in/Knock-out Confirmation
Genomic DNA from animal models are extracted and analyzed using Southern blot to confirm the knock-in or knock-out of a gene.
GMP QC Analysis Process
- Assay Development: A gene-specific hybridization probe will be prepared by PCR from the provided control plasmid and optionally confirmed by Sanger Sequencing. A pilot study will be conducted with the P32-labeled probe following our standard Southern blot procedure that has been validated as a platform method.
- Assay Validation: A partial validation will be performed to demonstrate the specificity of the assay (probe specificity), and sensitivity of the blots.
- Sample Testing: MCB, WCB, and EOPC along with negative and positive controls are tested to support cell bank genetic stability.