Peptide synthesis

Peptide synthesis turnaround depends on the number of peptides required, purification options, and the scale and complexity of each peptide.

AltaBioscience offers a fast turnaround for standard small-scale peptides, with completion generally in 7 – 10 working days. We can synthesise up to 576 non-purified peptides per batch in 6 – 8 working days with our Episcan peptide synthesiser.

Large-scale, complex, large numbers or highly purified peptides will extend the turnaround time. However, we appreciate that projects may run under high time constraints and are happy to discuss turnaround times and how best we can help you meet your deadlines.

At AltaBioscience, we provide various purity options ranging from crude-desalted to over 95% purity. Peptide synthesis may generate impurities alongside the desired peptide, such as truncated sequences, deletion sequences, incomplete deprotected sequences, racemised peptides or compounds from side reactions such as aspartimide formation or cysteine oxidation.

When ordering custom peptides, it is important to check whether the requested peptide purity level will suit the intended research applications. Crude peptides, without any purification, such as those obtained from the Episcan scale, are suitable for screening studies where a large number of peptides are initially tested before undertaking further studies. Standard purification to 80%-95% is suitable for applications such as polyclonal antibody generation and in-vitro assays, and peptide blocking studies, whereas higher purity over 95% is usually required for NMR studies, X-ray crystallography, and enzyme and structural studies.

Our peptide chemists can guide suitable purity levels for your required application. Contact our experts or learn more peptide purification and peptide analysis.

Peptide solubility as a guide is determined by the overall charge of the peptide and the environment it exists. Changing the pH can help in solubilising some peptides.

Care is needed when selecting your solvent, and consideration should be given to the assay in which you intend to use it; for instance, TFA may be toxic to cells in higher concentrations. DMSO is best avoided for peptides containing Cysteine, methionine and tryptophan, as it may cause oxidation. As a general rule, where possible, use volatile solvents, which can be removed by freeze drying to recover the peptide for further studies.

AltaBioscience offers a solubility test service which will provide information on the solubility of your peptide in 3 solvents. Due to the requirement to use additional peptides, this service is suitable for individual purified peptide orders of greater than 10mg amounts. Read more on peptide solubility and storage.

Determining the concentration of peptides or proteins can be achieved by either measuring the UV absorbance at 280 nm, reacting the proteins or peptides with dyes and/or metal ions in colorimetric assays (e.g., Bradford assay, Lowry assay, BSA assay) or by performing amino acid analysis, the latter being considered as the gold standard method.

Amino acid analysis is usually performed when the concentration cannot be determined by UV absorbance due to the lack of aromatic tryptophan and tyrosine residues in the proteins or peptides. Although amino acid analysis requires specialist equipment, it is a robust and highly sensitive method that quantifies the concentration of each individual amino acid in a sample. The protein or peptide concentration is therefore obtained by summing up the concentrations of the single amino acids. Amino acid analysis also has many advantages over colorimetric assays that can suffer from interferences when high concentrations of detergents or chaotropic agents are used. In addition, the dyes/metal ions in colorimetric assays may preferentially react with certain amino acids, whereas the amino acids react equally during the derivatisation step when performing amino acid analysis.

At AltaBioscience, we provide a comprehensive peptide analysis service. In addition to our peptide synthesis service, we also offer amino acid analysis for the absolute protein quantification of proteins and custom peptides. Our amino acid analysis service is accredited to ISO/IEC 17025:2017.