Peptide purity

Unless otherwise stated, peptides supplied by Isca Biochemicals have a minimum purity of  95%.  Note that this is the minimum purity normally acceptable and in reality the majority of peptides are synthesised to higher purity levels than this.  Purity is determined by HPLC and mass spectroscopy as standard with amino acid analysis, microanalysis or NMR also carried out if required.  For any given product, minor batch variations, which have no effect on the biological properties of the material, may take place due to manufacturing processes.  

Depending on the required purity and intended application, the final peptide is analysed as required. Peptides are purified by reverse phase high performance liquid chromatography (HPLC), ion exchange chromatography or gel filtration techniques, with the higher specification bioscience grade peptides (>95%) subject to the most rigorous purification.  Peptides of lower specification are similarly purified to the degree required. A lower peptide specification may be more cost effective and rapid to synthesise and so may be preferred for some applications.

Specific product purity

Specific analytical details for any product are given on the data sheet that accompanies the product.  When each batch of a peptide is made it is assigned a unique synthesis reference number, with an internal code for the purification details.  Together these make up the lot number.   An example is LL37 – CoA-0532AC.  LL37 is the product name, 0532 is the synthesis reference number and AC refers to the purification method.  This number is unique to each batch and and the original data can be made available on request.  In this instance the peptide purity is 97.1% and the net peptide content is 72%.   Where a data sheet is not available the peptide will have not been finally purified so the information on the website is shown as a guide only.  Once finalised, the data sheet will be provided with the product when it is sent out.

Net peptide content

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 consult the product data sheet for net peptide content information.