The peptides are supplied lyophilized and should be handled with the following considerations:
The peptides should be preserved at a cool dry, evades light place, seal.
Short term storage(2 to 3 months) of lyophilized peptide should be done in a freezer at -200C. For longer storage, we recommend storing the peptide in a deep freezer at -800C if available.
If peptide samples need to be frequently or periodically taken from the stock, it is recommended to make a series of aliquots from the stock.
Peptide sequences containing C, M, or W are prone to air oxidation. It is recommended to purge the air out of the vial and replace it with a blanket of nitrogen or argon.
The steps outlined below provides you with a method for determining the best solvent for a synthetic peptide based on its amino acid sequence. It is best to first solubilize a small aliquot of the sample, rather than the entire sample.
Assign a value of -1 to each acidic residue. The acidic residues are Asp (D), Glu (E), and the C-terminal -COOH. Assign a value of +1 to each basic residue. The basic residues are Arg (R), Lys (K), His (H), and the N-terminal -NH2. Calculate the overall charge of the peptide.
If the overall charge of the peptide is a positive value, you have a basic peptide. Initially try to dissolve the peptide in water. If the peptide does not dissolve, try 10% and higher solutions of acetic acid. If the peptide still does not dissolve, add TFA (<50ul) to solubilize the peptide and dilute to 1ml with deionized water.
If the overall charge of the peptide is a negative value, you have an acidic peptide. Initially try to dissolve the peptide in water. If the peptide does not dissolve, add NH4OH (<50ul) and dilute to 1ml with deionized water.
If the overall charge of the peptide is zero, your peptide is considered neutral. Neutral peptides may require the addition of organic solvents, such as acetonitrile, methanol, or isopropanol. The addition of denaturants, such as urea or guanidinium-HCL may also be required.
Business areas encompassed by PEPSYNTH products are
- Pharmaceutical Intermediates
- Intermediates for Personal Care Products
- Specialty Organic and Inorganic Chemicals
- Intermediates for Electroplating Chemicals
- Water Treatment Chemicals
- Flame Retardants