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Proteins FAQs

Creative Biolabs is dedicated to providing various protein products and protein-related services. At present, our scientific support team answers frequently asked technical questions (FAQs) about protein. If your question is still not answered, please contact us and we are happy to help.

  1. What products or services do you offer?
  2. We provide a variety of native proteins, small molecule antigens, active proteins, thousands of recombinant proteins, transmembrane proteins and semi-customized recombinant proteins. We also offer risk-free protein expression service such as custom membrane protein production service.

  3. What are recombinant proteins? What are the applications of recombinant proteins?
  4. Recombinant proteins are a manipulated form of protein, which are translated products of exogenous DNA in living cells. Recombinant proteins are produced in various ways by modifying gene sequences to produce large quantities of proteins. Simply, the production processes of recombinant proteins include molecule cloning and protein expression. Recombinant proteins have been used widely in medicine, research, and biotechnology and so on.

  5. Why do we choose your proteins or protein services?
  6. Currently, we have integrated multiple cutting-edge technologies and established a powerful protein production platform. Our custom service can generate highly purified recombinant proteins in different species by different expression systems to meet your requirements. We have a full range of recombinant expression systems include E. coli, Yeast cells, Baculovirus-Insect cells, mammalian cell and photosynthetic bacteria. Besides, our professional technical team provides comprehensive protein QC and COA report.

  7. Which expression system should we select in priority order?
  8. Generally, the difference of the products produced in different expression systems are the post-translation modification. Thus, the selection of an expression system mainly depends on your purpose of experiment. E. coli expression system is widely used in immune-related experiments, receptor and ligand binding experiments, cell experiments or drug screening experiments, enzyme activity experiments, etc. Yeast expression system and Baculovirus-infected insect cells expression system generally are applied in purified protein (structure, enzymology, drug discovery). Mammalian cells expression system is mainly used in purified protein (structure, enzymology, drug discovery), protein therapeutics and cell-based studies.

  9. What is the purity of each protein?
  10. The protein purity provided by us is higher than 85% as determined by SDS-PAGE.

  11. What validations have you performed for your protein?
  12. In general, we offer molecular weight, electrophoretic results (SDS-PAGE), concentration, purity, etc. Other detection results or services also can provide per your request, such as electrophoretic parameters, activity evaluation, sequence identification, tag removal service, endotoxin removal service, Western blot and MS validations.

  13. How do you determine the protein concentration?
  14. We often use three methods to measure the protein concentration including bradford method, BCA method, A280 method. Commonly, the bradford method is the most popular and widely used.

  15. What types of tags do you use for recombinant proteins?
  16. We offer various tags include His-tag, FLAG-tag, GST-tag, MBP-tag, combination tags (His-GST-tag, His-sumo-tag, His-MBP-tag) and so on.

  17. Can you remove the tag?
  18. Normally, not all protein tags can be removed due to some proteins will be significantly unstable after tag removal. Thus, if you need to remove the tag please contact us in advance. We will try our best to meet your special requirements.

  19. Can you remove the endotoxin?
  20. Yes. We can provide the endotoxin removal service and guarantee endotoxin level within 0.1 ng/μg (1 EU/μg).

  21. Can you provide corresponding antibody for this recombinant protein?
  22. Yes. We offer a full range of antibody development services against various antigens including proteins. Besides, we have powerful Magic™ membrane protein antibody platform (Magic™ Anti-Membrane Protein Antibody Discovery Services). Our scientists are committed to providing a comprehensive set of antibody development services form high-quality protein production for immunogen preparation to antibodies generation with high specificity and affinity.

  23. How to avoid inclusion bodies and improve soluble expression?
    • Proteins with high hydrophobicity or transmembrane domains, thus, it is essential to add fusion tags or add heat shock chaperones. Besides, a shorter induction time at low temperature or change to poor media also can improve soluble expression.
    • Incorrect disulfide bond formation. Add fusion partners such as thioredoxin, DsbA, DsbC to improve soluble expression. You also can clone in a vector containing secretion signal peptide or use gamiB (DE3) strains with oxidative cytoplasmic environment.
    • Incorrect folding. You can use a fusion partner or co-express with molecular chaperones. Other methods can be recommended to such as use strains with cold-adapted chaperones, supplement media with chemical chaperones and cofactors.

Other questions about the proteins, please contact us.

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For research use only. Not intended for any clinical use.