Although some peptides require a stronger solvent to be completely dissolved in the solution, as described above, sterile distilled water or conventional bacteriostatic water is effective in many cases and is the most commonly used solvent or diluent for reconstituting peptides. . Sodium chloride water is not recommended as it is prone to cause precipitation of acetate. The following is a simple typical example of reconstituting a peptide in a laboratory environment. This is only a general description of common laboratory procedures and is not specific to any peptide.
* IMPORTANT: Allow the peptide to reach room temperature before opening the container. For more information on maintaining the stability and integrity of your research peptides, please read our peptide storage page.
If you need to pay attention to bacterial contamination, you can also choose to pass the peptide solution through a 0.2μm filter.
Examples of using sterile water as a diluent:
Step 1 – Remove the plastic cover from the peptide bottle to expose the rubber stopper.
Step 2 – Remove the plastic cover from the sterile water bottle to expose the rubber stopper.
Step 3 – To prevent bacterial contamination, wipe the rubber stopper with alcohol.
Step 4 – Extract 2 mL (ml) of water from a sterile water bottle.
Step 5 – Insert 2 mL (ml) of sterile water into the peptide vial and allow the water to slowly enter the vial.
Step 6 – Gently rotate the solution until all peptides are dissolved – do not shake the vial.
Peptide reconstitution
Lyophilized peptide
Peptide reorganization
The peptide is typically provided in the form of a lyophilized (lyophilized) powder. Lyophilization is the process of removing water from a compound after freezing the compound and placing it under vacuum, changing the ice directly from solid to vapor without passing through the liquid phase. Lyophilized peptides are generally similar to small white “ice balls” which may have a fluffy or more granular appearance. Different freeze-drying techniques can produce larger (fluffy) or more compact (granular) lyophilized peptides.
Reconstituted peptide
Lyophilized peptides must be reconstituted before they can be used in the laboratory; that is, they must be dissolved in a liquid solution. Unfortunately, there is no “one size fits all” solvent to dissolve all peptides while maintaining peptide integrity and bioassay compatibility. Although sterile, distilled water or conventional bacteriostatic water is preferred, it does not dissolve all peptides. Therefore, researchers may have to take trial and error methods and try to dissolve the peptide in an increasingly strong solvent. Sodium chloride water is not recommended as it is prone to cause precipitation of acetate.
The polarity of the peptide is a major factor in determining its solubility. The basic peptide can be dissolved in an acidic solution, and instead, the acidic peptide can be reconstituted in an alkaline solution. In addition, hydrophobic peptides and neutral peptides containing many hydrophobic or polar uncharged amino acids should be dissolved in an organic solvent. Examples include acetic acid, propanol, isopropanol and DMSO. However, the amount of organic solvent should be small. Once the peptide is dissolved in the solution, it should be diluted with sterile water or bacteriostatic water. Sodium chloride water is not recommended as it is prone to cause precipitation of acetate. Importantly, peptides with methionine or free cysteine should not be dissolved in DMSO. Side chain oxidation may occur, making the peptide unsuitable for laboratory experiments.
Peptide recombination guide
How to recombine (mix) peptides
In general, it is recommended to first try to dissolve the peptide in a solvent that is easily removed by lyophilization. This is a precaution: if the initial solvent is not effective, it can be removed again by lyophilization. Often, researchers should first try to dissolve the peptide in sterile distilled water or conventional bacteriostatic water or sterile dilute acetic acid (0.1%). As a general guideline, it is recommended to test the solubility of a small portion of the peptide in the chosen solvent before attempting to dissolve the entire peptide.
Importantly, the initial use of sterile water (or dilute acetic acid) will allow the researcher to dry the peptide without any unwanted residue to prevent the peptide from dissolving. Once the initial ineffective solvent is removed, the researchers can try to dissolve the peptide in an increasingly stronger solvent.
In addition, the investigator should dissolve the peptide in a sterile solvent to provide a stock solution at a concentration higher than the concentration required for the assay. If the assay buffer is used first and the peptide is not dissolved, it is very difficult to recover the undoped peptide. However, the peptide can then be further diluted with assay buffer.
Actual implementation of the laboratory
Although some peptides require a stronger solvent to be completely dissolved in the solution, as described above, sterile distilled water or conventional bacteriostatic water is effective in many cases and is the most commonly used solvent or diluent for reconstituting peptides. . Sodium chloride water is not recommended as it is prone to cause precipitation of acetate. The following is a simple typical example of reconstituting a peptide in a laboratory environment. This is only a general description of common laboratory procedures and is not specific to any peptide.
* IMPORTANT: Allow the peptide to reach room temperature before opening the container. For more information on maintaining the stability and integrity of your research peptides, please read our peptide storage page.
If you need to pay attention to bacterial contamination, you can also choose to pass the peptide solution through a 0.2μm filter.
Examples of using sterile water as a diluent:
Step 1 – Remove the plastic cover from the peptide bottle to expose the rubber stopper.
Step 2 – Remove the plastic cover from the sterile water bottle to expose the rubber stopper.
Step 3 – To prevent bacterial contamination, wipe the rubber stopper with alcohol.
Step 4 – Extract 2 mL (ml) of water from a sterile water bottle.
Step 5 – Insert 2 mL (ml) of sterile water into the peptide vial and allow the water to slowly enter the vial.
Step 6 – Gently rotate the solution until all peptides are dissolved – do not shake the vial.
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