Why do proteins need to be lyophilized? What are the effects on proteins?

    Proteins are heat sensitive and lyophilization allows the protein to be stored with maximum activity, extended shelf life, and reduced transportation costs. The effects of lyophilization on proteins include the possibility of partial inactivation, aggregation and other problems. However, these negative effects can be minimized by adding protective agents, stabilizers, additives, antioxidants and controlling the various conditions of lyophilization.

Why add protectants to the protein solution before lyophilization? What are the protective agents commonly used by PrimeGene?

    Freeze-drying will have a certain effect on the activity of proteins, and the addition of a protective agent can reduce this effect and maximize the protection of protein activity. The usual protectants or stabilizers are sugars, polyols, certain proteins and amino acids. Our commonly used protective agents are: trehalose, Tween, etc.

The lyophilized form of the recombinant protein shipping at ambient temperature and the instructions indicate that it should be stored at -20ºC. Does this shipping method affect the activity of the product?

    The lyophilized powder product will not be affected when shipped at ambient temperature. Freeze-drying improves the stability of the protein product while reducing packaging materials and shipping costs. We have tested the shipping conditions of our freeze-dried products to ensure product quality.

What is Trehalose and what is the function of Trehalose in the formulation?

    Trehalose is a non-reducing sugar that does not react with amino acids or proteins in the Maillard reaction. It is found in many plants and animals in nature. Trehalose stabilizes proteins against damage caused by freezing and also makes them more water-tolerant when freeze-dried, thus making it less likely that the product will precipitate upon re-solution.

Does trehalose interfere the conjugation reaction?

    The presence of trehalose may interfere with the successful binding of proteins. This will depend on the method of conjugation and customers are advised to do the relevant research before purchasing the product.

What does "mg/g" mean on the product label?

    The quality of recombinant protein is not necessarily the same as that of freeze-dried powder because of the addition of protective agents or stabilizers to the solution before freeze-drying. Mg/g refers to the mass (mg) of recombinant proteins per gram (g) of freeze-dried powder.

Can the protein be used for in vivo experiments? What is the recommended concentration?

PrimeGene Protein does not perform any in vivo testing. You are advised to look for proteins that have been tested for biological activity, and determine the working concentration by reviewing the references for the in vivo application of the product.

If the product contains trehalose, will in vivo experiments affect the animals?

Trehalose is unlikely to affect in vivo experiments. It has been approved for use as an adjuvant in human injectable drugs. The trehalose used in PrimeGene is derived from Saccharomyces cerevisiae and has a purity of at least 98.5% as determined by HPAE.

In what application can the product be used?

    Our products can be classified according to scientific fields, but no clear guidance is given on their specific applications. Since proteins can be explored for multiple applications and methods of application according to their functions, we recommend our customers to conduct experiments according to the literature or to explore their own application methods based on scientific research.

Why do some proteins come with labels?

    The tagged proteins are generally used to meet the experimental requirements of some customers. For example, affinity columns can be used for His-tag and GST-tag; FC fusion proteins can be used for antibody studies, etc.

The amino acid sequence of some products like 1002-08 are not shown on the website, , Can they be provided by PrimeGene?

    If the amino acid sequences of some products are not shown on the website, they may not be provided as confidential information, but some products can provide protein Accession# and GeneID for reference. If you have any questions, we recommend you to call the customer service hotline at 400-821-3475.