CPC can indeed aliquot any order to your specifications. Through aliquotting your order into smaller quantities, this service will allow you to store and access your peptide with ease and also gives you the ability to standardize your protocols. Perhaps most important, the peptide will enjoy greater stability in the long run by preventing contamination from frequent opening of the container. Repeated thawing/freezing and opening/closing of the container will invariably introduce moisture into the system. This could lead to bacterial degradation, peptide oxidation, and aggregation, lowering the purity of your peptide and causing loss of continuity in future experiments. Weights for aliquots 1 mg and over will be determined by our balance scale. All aliquots less than 1 mg will be aliquoted volumetrically for more precision than our balance offers.
CPC performs a very specialized pooling service for its customers. We can customize this to suit any customer’s needs, but we have a general protocol which is very effective at demonstrating the contents of a pool. First, subpools of 20 peptides are created. MS is run on these pools to display each peak for each peptide contained in the subpool. In most cases, the peptides are of a different enough mass to clearly point out each peak. However, if the masses of two peptides are very similar, it may be difficult or impossible to discern. After all of the subpools have been created, they are then combined into a master pool. Finally, MS is performed on the master pool with the notion of identifying one peak from each individual subpool. In doing so, this demonstrates that each subpool and subsequently each peptide are present in the master pool.
CPC can produce all commercially available modifications with the exception of radiolabeling. CPC is happy to provide you with answers to any of your technical questions with regards to modification. For a list of peptide modifications and some intended uses, please visit the peptide modification page.
Catalog peptides are commercially available, published sequences. Commonly used catalog peptides are frequently produced in bulk at purities exceeding 95%, and they are generally kept in-stock. Producing these peptides in larger quantities allows companies to sell them at lower prices due to the bulk process involved. Custom peptides, on the other hand, are not public domain. Certain changes or modifications to catalog peptides must be ordered as a custom order for this reason. When ordering a custom peptide, the 2 most determinate factors are purity needed and sequence length. The time length involved in producing a custom peptide at CPC is generally 2-3 weeks.
Every peptide (including crude) is shipped with HPLC and MS. A bonus that CPC provides with its QC package is a recommended solubility test on each peptide. This solubility test utilizes solvents that are applicable for your experiment (water is the first choice), and can be customized according to the customer’s specifications. The test will save you time and effort in trying to determine the solubility and will also save peptide because you won’t need to use a small sample for testing if you do not have the ability to lyophilize the peptide.
All peptides are shipped directly to the end-user from our San Jose, CA office by FedEx overnight service. On the day of the shipment an e-mail is sent to the end-user confirming the shipment and providing a FedEx number in order to track the package if needed.
Each peptide is shipped at ambient temperature and accompanied with desiccant to absorb excess moisture. Various tests have revealed shipping under these conditions has no impact on the viability and shelf-life of the peptides. However, upon receipt of the product by the end user, it should be stored immediately at -20° C or lower.
CPC has produced a peptide of 130 amino acids in length, but in general, peptides of more than 30 amino acids can be problematic. Solubility is one of the most important factors to consider when designing a peptide as it will affect the purity attained since HPLC is performed in solution. The more hydrophobic residues in the sequence, the less soluble the peptide is. Certain sequences can also aggregate which will lead to difficulties in production. CPC has over 100,000 peptides worth of peptide design experience at your disposal, and we are happy to assist any questions.