What type of peptide chemistry does Pi Proteomics use?

Pi Proteomics uses solid phase Fmoc chemistry.

What modifications can you perform?

We can perform a host of modifications to your peptide. Please email us your request and we will respond promptly.

What Quality Control documentation do you supply?

A Certificate of Analysis, a mass spectrometry report and a HPLC analytical report are provided with all purified peptide orders (“crude” purity peptides receive a Certificate of Analysis and a Mass Spectrometry report). An Amino Acid Analysis (AAA) is available upon request at an additional cost. AAA is used to determine peptide content and composition. Peptide Sequencing is available upon request at an additional cost. Peptide Sequencing is used to validate that the proper peptide sequence was synthesized.

How do you ship the peptide(s) I ordered?

We ship all peptides by FedEx Standard Overnight. We will either ship peptides on your account or bill you separately.

How should I store the peptide(s)?

We recommend keeping the vial capped at all times.  Additionally, we recommend adding nitrogen or argon to the vial in order to blanket the peptide. The nitrogen or argon will help reduce the chances of oxidation of the following amino acids: cysteine, tryptophan, and methionine. For short term storage (1 week to 3 months) use a -200C freezer, for long term storage (3months +) use a -800C freezer. Try to avoid repeated freezing-thawing of the peptides. If peptide samples are needed frequently or periodically, we recommend making a series of aliquots from the stock peptide.

How are the peptides supplied to me?

We ship all peptides lyophilized and sealed in a glass vial. The weight on the vial is the peptide gross weight.

What is the difference between “Gross Weight” and “Net Weight”?

Unless requested differently, all peptides are shipped according to its gross weight. Gross weight is the actual weight of the lyophilized product. Gross weight includes any impurities such as residual water and/or salts from the counterions accumulated during the synthesis and purification processes. Net weight is the amount of actual peptide present minus the impurities. In order to find net weight, an AAA must be performed.

What does the purity mean on the HPLC report?

The purity of the peptide is determined by HPLC analysis with detection at 220 nm. The purity of the peptide does not take into account water and salts that are usually present in the sample. Other contaminates found with the peptide may include sequence deletion, truncation and incompletely deprotected sequences. The peptide’s purity is the amount of correct peptide relative to all analytes that absorb at 220 nm.

Do I need to add a cysteine to my peptide for conjugation?

No, generally speaking. However, if the peptide sequence selected is at the terminal position of the n-term of the protein, a cysteine needs to be added to the c-term of the peptide for conjugation.

Does Pi Proteomics conjugate peptides?

Yes, we can conjugate your peptides to KLH, BSA, RSA, OVA, THY, MAP for polyclonal or monoclonal antibody production. We can also conjugate your peptide to FAM, Biotin, Rhodamine, FITC, Oregon Green, and Texas Red to name a few.