Specific reconstitution and storage instructions for each product are on the Certificate of Analysis shipped with your order.
1. How should I store your products?
Our lyophilized proteins are stable at room temperature, though we recommend storing them at -20°C to -80°C for the best long-term stability. Once reconstituted, we recommend short-term storage at 4°C. For extended storage, keep working aliquots at -20°C to -80°C. Avoid more than one freeze-thaw cycle per aliquot to help preserve full activity.
2. What quality control testing do your proteins undergo?
Every batch goes through a comprehensive quality control process, including purity assessment, identity confirmation, endotoxin testing, and a functional bioassay to confirm biological activity. This gives you confidence that every vial performs consistently, batch after batch.
3. What endotoxin level can I expect from your animal-free proteins?
Our animal-free proteins are guaranteed to have an endotoxin level below 0.1 EU/µg of protein, with actual measured values typically running well below this figure.
4. How is the bioactivity of your proteins confirmed?
Every batch is tested in an appropriate biological assay to confirm it meets our quality control activity parameters before release, so you can expect consistent, reliable performance from batch to batch.
5. Why are your proteins lyophilized?
Lyophilization (freeze-drying) extends protein shelf life and simplifies shipping by removing the need for cold-chain delivery. After reconstitution, the protein is ready for use. Long-term stability studies confirm that activity is retained under the recommended storage conditions.
6. How do you calculate the specific activity of a protein?
We determine specific activity by testing each batch in a validated bioassay against an established reference standard. Biological activity is measured in units and then divided by the amount of protein (in milligrams) to give specific activity in U/mg. This value shows not only how much protein you receive, but how biologically potent it is.
7. What is an International Unit (IU)?
An International Unit (IU) measures biological potency, not protein mass. IU values are assigned against an internationally recognised reference standard. This puts potency on a common scale across suppliers and batches. Where such a standard is available, we report activity in IU.
8. Are your products sterile?
Our proteins are processed using aseptic techniques throughout manufacturing and are sterile-filtered before lyophilization. For applications that require guaranteed sterility after reconstitution, we recommend passing the reconstituted protein through a 0.2 µm filter suitable for biological fluids.
9. What is the shelf life of your products?
Our lyophilized proteins carry a guaranteed shelf life of 12 months from the date of manufacture when stored as recommended. If you need a product recertified beyond that window, we're happy to discuss extending shelf life through additional testing.
10. What is the difference between your animal-free and non animal-free recombinant proteins?
Our animal-free proteins are produced using expression and purification systems that avoid any animal-derived components. This reduces lot-to-lot variability and supports chemically defined, xeno-free workflows, valuable for stem cell research, organoid systems, and cell and gene therapy applications.
11. How quickly can I expect delivery?
Our in-stock products typically dispatch within 2 to 3 business days. For products still in development, please contact us so that we can provide you with an estimated release date, as well as keeping you updated on progress.