ChinaPeptides(QYAOBIO)

If you do not know how to dissolve your sample properly, especially how to dissolve hydrophobic peptides, it will often make it difficult for you to carry out the experiment. Sample consumption is inevitable to determine the optimal dissolution conditions of the peptide. If the consumption is too much, the remaining key peptide sample may not be enough to complete your subsequent experiments.

We provide solubility testing service to help you deal with hydrophobic peptides in a more customized way. You will not need to estimate the solubility of the sample through additional experiments, we will provide you with a complete, customized peptide solubility properties report, specifically for you to solve the problem of peptide dissolution properties.

Suitable polypeptide dissolved polypeptide analysis experiment is an important factor for success. Improper or inadequate dissolution of peptides can lead to inaccurate calculation of peptide concentrations and may cause experimental errors or lead to experimental failure.

It is recommended that a small amount of peptide be used first to test the optimal solution. Only when the peptide is completely dissolved can the solution be added and diluted to the final concentration. That is, dissolve first and then add buffer. Note that the peptide is always added to the appropriate solvent to stir, not otherwise.

Preservation of freeze-dried polypeptides

All products labeled "freeze-dried" must be kept in freezing conditions, preferably at -20 ° C, but most peptides may remain active for several years if kept below -80 ° C.

When using frozen products, the bottle or test tube should be raised to room temperature in a drying oven with fresh desiccant before opening the lid. For products stored at -20°C, the process takes an hour or more, depending on package size. Otherwise, when the bottle is opened, water vapor enters and causes the peptide to condense, reducing its stability. Once opened, should be quickly weighed, and immediately closed to avoid deliquescence, especially hydrophilic peptide should pay more attention to.

Preservation of polypeptide solutions

Polypeptide solutions are much less stable than dry powders. For best results, follow the following principles:
Repeated freezing and thawing damage the activity of the peptide, so it is recommended to separate into small packaging. Defrost as much as you need and discard the rest after use.
Soluble in PH5-7 sterile buffer solution, stored at -20° C.
Peptides containing Cys, Met, Trp, Glu and Asp are easy to oxidize and should be stored in an oxidant-free environment.
Since bacteria can degrade peptides, they must be filtered for removal before storage.

What is the basic principle of peptide synthesis?

Solid synthesis of polypeptide is a major breakthrough in polypeptide synthesis chemistry. Its main feature is that the intermediate product is not purified, and the synthesis process can be continuous, thus laying a foundation for the automation of peptide synthesis. At present, fully automatic polypeptide synthesis is basically solid phase synthesis.

How does the peptide dissolve to achieve the maximum dissolved concentration?

Dissolving peptides is very complicated and it is often difficult to identify a suitable solvent all at once. Usually a little test is taken first, do not dissolve all before determining a suitable solvent. For conventional dissolution, there are several recommendations: (1) ultrasound can increase the solubility of polypeptides; (2) 10% acetic acid helps dissolve basic polypeptides; (3) 10% ammonium bicarbonate helps dissolve acidic polypeptides; For peptides with very low solubility in aqueous solutions, try to dissolve them with organic solvents (such as DMSO, isopropyl alcohol, methanol, acetonitrile) first. Once the peptides are completely dissolved, gradually dilute them with water to the specified concentration.

How do you define the purity of a peptide?

The purity of peptides is usually determined by HPLC with a standard acetonitrile gradient of 1% per minute. During synthesis, the efficiency of cross-linking between amino acids is not always 100%, resulting in a series of amino acid deficient impurities. Most of these amino acid-deficient impurities are removed during purification, but a few have chromatographic properties very similar to those of target peptides. These amino acid deficient peptides remain in the polypeptide sample and constitute the remaining percentage points.

How to check the quality of synthetic peptides?

The molecular weight of the peptide is usually determined by mass spectrometry to determine whether the product is correct. MS results can also reveal most of the major impurities. If necessary, net peptide content detection, such as amino acid analy

Why is the synthetic yield or purity of some peptides relatively low?

Peptide synthesis is quite different from lead synthesis. There are very few leads that cannot be synthesized, but there are often peptides that cannot be synthesized. Such as Val, Ile, Tyr and Trp, Leu, Phe, Gln, and Thr near or repeat these amino acids, polypeptide chain in the process of synthesis can not completely stretch dissolved, synthetic efficiency decline.

How long is the polypeptide used to do immunity appropriate?

Generally about 10-15 amino acids, of course, longer immune effect is better, but the cost of synthesis will increase. MAP peptide is expected to be longer than 15aa, the effect is better. In addition, the immune effect of peptides below 10aa was poor.

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