Peptide Handling Guideline

Reconstitution Guideline

Proper peptide handling and solubilization is the starting point of a successful bioassay project, and we believe this handling guideline will help you dissolve your peptides properly. On CoA along with each peptide delivery, you may also see reconstitution conditions which we certainly have used in the peptide refinement process – this is for your reference only, you may dissolve your peptide in another type of solvent according to your assay needs. The benefits of collagen in the body

– Only use a little aliquot of peptide to test the dissolution method. Once satisfied, apply to the bigger aliquot as needed. 

– In theory, solvent used should be the solvent that will facilitate or be suitable for your experiment. However, we need to also keep in mind that there might be a problem sometimes to find an “ideal” solvent that can solubilize peptides, maintain their ethics and be compatible with biological assays.

-For first solvent used should be the most appropriate one. For example, for a very hydrophobic peptide, it is better to reduce it in a little amount of organic and natural solvent (such as DMSO or acetonitrile) before applying the aqueous solution. In other words, adding organic and natural solvent to a suspension of hydrophobic peptide in aqueous solution is not likely to help much in dissipating.

– Peptide solution might be unstable at conditions even lower than -15? C. As such, a peptide solution once well prepared should provide as soon as possible.

What solvent(s) I am able to use to melt my peptides?

If it is a short peptide which is 5aa or less, try sterile unadulterated water first and it is likely to melt.

For other peptides, the entire charge of the peptide will help determine which initial solvent to use. Assign a worth of -1 to acidic elements which include Asp(D), Glu(E), and the C-terminal free acid(-COOH). Assign a value of +1 to basic residues which include Afeafef (R), Lys (K), His (H), and the N-terminal free amine(-NH2). Calculate the overall charge of the whole peptide.

1. In case the overall charge of the peptide is positive (a basic peptide), try to break down the peptide in clean and sterile distilled water first. In the event water fails, add ~20% acetic acid solution. In the event the peptide still will not dissolve, add drops of TFA ( < 50ul), or use zero. 1%TFA/H2O to solubilize the peptide. Then dilute the peptide solution to the required concentration.

2. If the overall charge of the peptide is negative (an acidic peptide), try to dissolve the peptide in sterile distilled water first. If the peptide continues as obvious particles, sonication can be tried. In the event water fails, add NH4OH ( <50ul) or zero. 1%NH4OH drop-wise. Then water down the peptide answer to the desired concentration. If the peptide contains Cys, do NOT use basic alternatives (NH4OH), but use DMF instead.

3. Peptide whoever overall charge is no (the peptide is considered neutral). It usually dissolves in organic and natural solvents, such as acetonitrile, methanol, or isopropanol. If that is not dissolve completely:

a) For peptides that usually tend to aggregate (due to the hydrophobic interaction), the addition of denaturants, such as 8M urea or 6M guanidine-HCl, may also be required.

b) To get very hydrophobic peptides (containing more than 75% hydrophobic residues), add DMSO drop-wise (use DMF instead for Cys containing peptides), and then dilute the solution with water to the desired concentration.

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