A focused approach to measurement in expression and purification workflows.
His-tagged proteins are widely used in recombinant expression systems for their ease of detection, purification, and downstream handling. But accurately measuring how much tagged protein is present — particularly in crude lysates — remains a key challenge in early-stage development.
Why His-tag quantification matters
Measuring the concentration of His-tagged proteins enables:
- Screening expression levels across constructs, hosts, or conditions
- Assessing yield and recovery after purification steps
- Normalising input for binding, activity, or structural assays
- Making fast, informed decisions during clone or process optimisation
Total protein assays like BCA or Bradford don’t distinguish between your tagged protein and other proteins present, especially problematic in crude samples.
Common limitations of standard methods
Many researchers turn to ELISA or Western blotting for tag-specific detection. While these methods offer specificity, they come with trade-offs:
- Require validated anti-His reagents
- Often involve multiple steps and extended incubation times
- Less practical for screening larger numbers of samples
They’re useful for confirmation, but not ideal for routine quantification during optimisation.
Where Amperia™ fits
The His-tag Protein Quantification Kit, designed for use with the Amperia™ system, enables targeted measurement of His-tagged proteins using Redox Electrochemical Detection (RED).
Key benefits:
✔ Measures His-tagged protein directly — not total protein
✔ Works with both crude and partially purified samples
✔ Simplified workflow with minimal hands-on steps
✔ Ideal for expression screens, construct comparisons, and early process development
This allows researchers to generate reliable, interpretable data earlier in the workflow — without needing purification first.