Cellsciences

Cellsciences For nearly two decades, Cell Sciences has been a worldwide provider of the highest quality antibodies, proteins and immunoassay kits available for use in life sciences research.  We offer a wide range of products for research in human, non-human primate, and small and large animal models.

Our products include ELISA and ELISPOT kits, flow cytometry reagents, monoclonal and polyclonal antibodies, native and recombinant proteins, cell lysates, and other associated reagents. These products address research in human, non-human primate, and small and large animal models. Cell Sciences offers a diverse range of research and development tools including cytokines, chemokines, CD antigens, adhesion molecules, ECM molecules, growth factors, hormones, enzymes, kinases, phosphatases, signal transduction mediators, viral proteins, and toxins.

We are passionate about providing the highest quality products and customer support to advance research and product development in fields such as immunology, inflammation, innate immunity, developmental biology, apoptosis, cell differentiation, cancer, stem cell research, coagulation, thrombolysis, hematology, endocrinology, neurobiology, angiogenesis, tissue engineering, and wound healing.

Our focus on satisfying our customer's needs for research and development reagents, technical data and technical support is what drives us to be your catalyst for discovery.

Cellsciences What are the Storage and Stability recommendations for your proteins and antibodies?

Proteins comprise a heterogeneous class of macromolecules that are often unstable during storage. If appropriate buffer conditions are not maintained, proteins may become insoluble or function improperly. Proteins can lose activity as a result of suboptimal buffer conditions, proteolysis, or aggregation. In the laboratory, purified proteins usually need to be stored for extended periods of time and need to retain their original activity and structural integrity.

The stability of proteins can vary from a few days to more than a year and is dependent on the nature of the protein and storage conditions. Optimal conditions for storage are distinctive to each protein.  Some proteins and monoclonal antibodies are typically stored in solution at 4°C but must be kept sterile or contain additives to prevent microbial or proteolytic degradation. Anti-microbial agents such as 0.1% sodium azide (NaN3) or 0.01% thimerosal inhibit microbial growth.  Metal chelators such as 1-5 mM EDTA avoid metal-induced oxidation of –SH groups and help to maintain the protein in a reduced state.  The reducing agent dithiothreitol (DTT) at 1-5 mM can help to maintain the protein in the reduced state by preventing formation of intramolecular and intermolecular bonds between cysteine residues.

Freezing at -20°C or -80°C is the most common form of cold protein storage. However, because freeze-thaw cycles decrease protein stability, samples need to be prepared in single-use aliquots so that, once thawed, the sample will not have to be refrozen. Another method to increase stability is the addition of 25-50% glycerol which will prevent freezing at -20°C.  This allows the repeated use of a protein from a single stock without thawing.  

Lyophilization allows for long-term storage of protein with little threat of degradation and has become one of the most common methods for manufacture for recombinant proteins.  It has the advantage that vials may be stored for extended periods of time before reconstitution.  However, the protein still must be reconstituted before use, and once it is reconstituted, the protein needs to be aliquoted and frozen like a liquid formulation.