Protein on Demand™ Semi-Custom Recombinant Proteins

In need of small to mid-scale recombinant proteins customized with the tag and expression system to accelerate your research?

Cannot afford the custom protein expression services most providers offer?

Aviva Systems Biology offers Protein on Demand, a catalog of semi-custom recombinant proteins.

  • 300,000 protein targets across a wide variety of species.
  • Customize the tag and expression system with up to 2 tags and 4 expression systems.
  • Small quantities available: 50 ug – 1 mg.
  • Regardless of your application, Protein on Demand has the unique recombinant protein you need to succeed.

Please note that not all tags and expression systems are available for each protein. Based on protein expression experience, the ideal tags and expression systems are available for selection for each protein. If you would like for Aviva to try a tag not listed, please contact us via email at with your details and we can work with Aviva to assess feasibility prior to order placement.

How to Customize

Our technical support team will guide you through the protein configuration steps, just click the button below!



Please note that selection of your tag and expression host does not guarantee product delivery. Every attempt will be made to manufacture your selection as requested. In a low number of circumstances, a selected tag may not yield sufficient protein expression for delivery. In such cases, customer service will contact you with the experimental findings and discuss alternative options on available protein tags.

Frequently Asked Questions

1. How do I customize a Protein on Demand protein?

Use the configurator that is found on each product page. Use the drop-down arrows to select from available tag, expression systems and size.

2. How long does it take to receive my protein?

The minimum production time is 4-6 weeks in the E. Coli expression system. However, each expression system is unique and may take longer. Production time in baculovirus can be up to 11-12 weeks. Before placing your order, our customer service team will confirm all details with you, including the estimated delivery time.

3. Can I change the buffer?

Protein on Demand customization and pricing does not include the option for buffer changes. However, we can confirm if a buffer change can be accommodated at an additional cost.

4. The tag I want on my protein is not available from your menu. Can I still request this tag?

We show the most likely tags to work for the expression of each protein. If there is a different tag you would like to use, please contact our Customer Service team at and we can work with Aviva to determine if an alternate tag may work before placing an order.

5. I cannot find the protein I need produced in the Protein on Demand catalog. Can my protein be custom made?

Yes! Aviva have a very experienced custom protein expression and production team that would love to help you. Fill out their simple Custom Protein Quote Request Form to start the conversation. Note that minimum quantities may need to be met for a full custom.