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.

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Supported Affinity Tags

His-Tag

Polyhistidine tags for metal affinity chromatography

  • 6x histidine repeats
  • Ni²⁺ affinity resins
  • Suitable for native conditions

Twin-Strep-Tag

Twin-Strep-Tag for biotin-based purification

  • Mild elution conditions
  • High specificity and low background
  • Compatible with functional studies

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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.

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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.