Technical support

Product Use

All products supplied are potentially hazardous and are strictly for research purposes only. Products are not supplied for pharmaceutical, household, food, cosmetic or any other human use. Products are strictly for use by qualified personnel trained in laboratory procedures and familiar with the potential hazards of such products. As research chemicals, the potential hazards are often not known and an absence of an explicit warning does not mean that no hazard exists. It is the users' responsibility to ensure that appropriate safety precautions are taken at all times.

Product Appearance

Some products, especially those supplied in small quantities or as lyophilized solids, may be difficult to visualise. These products may appear as a clear, thin film on the bottom and walls of the vial.

Peptide storage and stability

We recommend that peptides supplied by Isca Biochemicals are stored frozen (-20°C), desiccated and in the dark. Peptides stored in this way should be stable for at least 6 months after leaving our laboratories. We recommend the avoidance of storing peptides in a frost-free freezer, as changes in moisture and temperature may affect stability. We also recommend avoidance of multiple freeze/thaw cycles. Before use, and prior to opening the vial, the peptide be allowed to equilibrate to room temperature (~1 hour).

Peptide storage in solution

Peptides in solution are less stable than when freeze dried. This is especially important for peptides whose sequences contain amino acids such cysteine, methionine, tryptophan, asparagine, glutamine, and N-terminal glutamic acid. Consequently, peptides should be stored in solution for as short a time as possible. We recommend a maximum of one week and the stock solution should also be stored frozen and in the dark when not in use. Peptides stored in solution can occasionally be susceptible to bacterial degradation. We recommend the use of sterile solutions or passing the peptide solution through a 0.2 μm filter to remove potential bacterial contamination whenever possible.

Temperature during Shipping

Many of our products are refrigerated or frozen for long-term storage but short periods at higher temperatures than those recommended (< 1 week, such as during shipping), will not affect the product life or efficacy. If there are any exceptions to this rule we will make it clear in the product specifications and ship the product appropriately (using blue or dry ice).

How to dissolve peptides

Where possible we provide specific solubility instructions for dissolving peptides. If specific instructions are not available, the following guidelines can be used. Most peptides are soluble in distilled water. If they do not completely dissolve, the addition of 1.0 M acetic acid for basic peptides (those containing arginine, lysine or histidine) or 1.0 M ammonium hydroxide for acidic peptides (those containing aspartic acid or glutamine) may help. Solubilisation of extremely insoluble peptides can be assisted with 10% DMSO, although the use of DMSO as co-solvent may interfere with some biological assays. Sonication can also be a useful aid for solubilizing peptides. When solubilizing peptides, it is recommended that the peptide be dissolved to the highest possible concentration, and then diluted with water or buffer to the working concentration. The buffer should only be added when the peptide is completely solubilized as salts may cause aggregation.

Purity of peptides

Unless otherwise stated, peptides supplied by Isca Biochemicals have a purity of >95%. 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. Details are given on the data sheet that accompanies the product and the original data will be made available on request.

Purification and quality control

Depending on the required purity and intended application, the final peptide is analysed to the extent 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 is preferred for some applications.

Quality control

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 - please contact us for details. We believe that the purity of any peptide supplied by Isca Biochemicals will match or exceed the purity of the product originally reported in the scientific literature.

HPLC

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 analysis

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

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

Microanalysis may also be provided as an additional service, and can also be used to determine net peptide content.

Contact us

If you have any product queries or technical support questions, please contact us by phone or email, or the contact form below.

email: [email protected]

Telephone: +44 (0)1392 422205

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