Affinity tag purification is a key step in our protein production workflow, enabling rapid, high-purity isolation of target proteins for downstream assays. Our platform uses two primary affinity tag systems optimized for different experimental requirements.

Supported Affinity Tags

Twin‑Strep‑Tag (Default)

Our default purification tag due to its high affinity and specificity, enabling excellent yields and clean eluates. Highly interoperable with our BLI/SPR measurements.

Other Tags

On demand, we can also work with other tags such as His, Fc, or lab‑specific alternatives. Tag choice depends on your protein and downstream requirements.

Tag Positioning

C-terminal placement (default): We use C-terminal tags for 90% of proteins because the tag only gets expressed if the entire protein gets expressed. This prevents purification of truncated proteins that could occur with N-terminal tags if protein expression stalls. N-terminal placement (on request): Available through the Foundry portal when needed, such as when the binding site is close to the C-terminus and might be affected by tag placement. All tags include a GS linker for proper spacing and minimal interference with protein function.

Workflow Integration

Purified proteins from this process are directly used in downstream assays including:
  • Binding assays (BLI, SPR)
  • Structural analysis
  • Functional studies
  • Quality control measurements
Tag selection and positioning can be customized based on your specific protein and experimental requirements through the Foundry portal.