Isca routinely synthesises difficult peptides (>100 amino acids) and we can synthesise peptides with a wide and increasing range of amino acid modifications including N-terminal, C-terminal and side-chain modifications, multiple disulphide bridges, fluorescent labels, D-amino acid and stable-isotope incorporation, biotinylation, glycosylation, post translational modifications, PEGylation and more. Standard peptides are routinely provided as free N-terminal amines and C-terminal acids, although N-terminal acetylation and C-terminal amidation can be offered at no extra cost.
A typical custom synthesis peptide run will yield between 5 - 50mg of the peptide in question, depending upon the number of amino acids and complexity of the product. However we have capacity for larger scale synthesis and are happy to discuss the provision of multi-gram quantities. Our custom peptide synthesis scientists are ready to offer reliable, confidential and constructive advice and a comprehensive quotation for the synthesis of the peptides that you need.
Purification and quality control
Isca Biochemical standard peptide purity is >95% but this level of purity is not always required for custom peptides, particularly when it impacts costs and synthesis times. Also please note that the majority of peptides supplied by us are in freeze dried form and will contain counter ions and physically bound water as a result of cleavage from resin, hplc and drying. These counter ions have no effect on the biochemical properties of the peptide but do have the effect of reducing the mass of peptide present in a given sample, usually to >70%. This may be confirmed by further analysis. Please let us know your purity specifications at the outset of a project to make sure we provide the most appropriate product for your requirements.
Peptide and biochemical purity is assessed using an array of techniques including HPLC, chiral HPLC, NMR, microanalysis, high voltage electrophoresis, melting point, optical rotation, TLC, and mass spectrometry as appropriate. All data is kept on file and available for inspection on request.
Peptides purified by reversed phase HPLC or ion exchange chromatography have their purity given as the area under the curve of the major peak when analysed at a specific wavelength, usually 230nm.
Mass spectroscopy analysis is performed to in order to conform the identity of the final product. A copy of the mass analysis is supplied as part of the datasheet delivered with the peptide.
Amino acid analysis can be provided as an additional service to determine peptide composition, and can also be used to determine net peptide if required.
Microanalysis may also be provided as an additional service, and can also be used to determine net peptide. Please discuss this option at the start of the project if microanalysis will be required.
Please contact us with your requirements - we look forward to hearing from you