- If I have any questions about your peptide services who do I contact?
- How do I order peptides?
- What´s the price for a custom synthesized peptide?
- What means "purity" and why do peptides have to be purified?
- Which purity degree do I need for my peptide?
- What's the IUPAC amino acid code?
- Which modifications do you offer?
- When do I need N-terminal acetylation or C-terminal amidation?
- How do you control the high quality of your peptides?
- What is MALDI-ToF?
- When will I receive my peptide?
- How do I store my peptides?
- How do I handle my peptides? What do I do if my peptide refuses to dissolve?
- Do you offer Peptide Arrays?
- What if metabion does not succeed in delivering the requested peptide?
1. If I have any questions about your peptide services who do I contact?
If you cannot find an answer in our "FAQ-catalogue" just contact us.
The easiest way is to write an email to peptides@mymetabion.com
We will answer your question as soon as possible.
2. How do I order peptides?
There are different possibilities:
Via our online order system
or
via email to peptides@mymetabion.com with the following information:
- Shipping and billing address
- Sequence (1 letter code, see FAQ 6) including potential modifications (kind and position)
- Quantity you would like to order in mg
- Desired purity in %
If you have any question, just contact peptides@mymetabion.com
3. What´s the price for a custom synthesized peptide?
If you need a linear peptide at a length between 8-25 amino acids you can look at our online price list:
Here you will find the prices per amino acid (AA) for different purity grades and delivered quantities.
For any special request, which you may not find in our pricelist, please contact peptides@mymetabion.com. For a quote, please indicate the following:
- Shipping and billing address
- Sequence (1 letter code, see FAQ 6) including potential modifications (kind and position)
- Quantity you would like to order in mg
- Desired purity in %
4. What means "purity" and why do peptides have to be purified?
A purity of 95% means for example that 95% of the sample contains full length peptides. The other 5% are truncated synthesis fragments. Residual toxic reagents have to be removed. Coupling is never 100% efficient. During synthesis truncated and deletion sequences accumulate which might interfere with the activity of the peptide.
5. Which purity degree do I need for my peptide?
This depends on the application. For immunological applications (raising antibodies), 70% purity is excellent. For peptide library binding screening, crude or 70% purity is also fine.
For cell biological studies, such as cellular activation or drug screening in cell culture, 95% purity is essential.
For structural studies (NMR, X-ray, Mass Spectrometry) or receptor / ligand studies, 95% purity is advisable.
6. What's the IUPAC amino acid code?
| Alanine | Ala | A | Methionine | Met | M |
| Cystein | Cys | C | Asparagine | Asn | N |
| Aspartic Acid | Asp | D | Proline | Pro | P |
| Glutamic Acid | Glu | E | Glutamine | Gln | Q |
| Phenylalanine | Phe | F | Arginine | Arg | R |
| Glycine | Gly | G | Serine | Ser | S |
| Histidine | His | H | Threonine | Thr | T |
| Isoleucine | Ile | I | Valine | Val | V |
| Lysine | Lys | K | Tryptophane | Trp | W |
| Leucine | Leu | L | Tyrosine | Tyr | Y |
7. Which modifications do you offer?
C-terminal amidation, N-terminal acetylation, biotinylation, fluorescent labels, phosphorylation, cyclization, incorporation of D amino acids and many more. If you have read about a modified peptide in a scientific article, we would be happy if you can provide us with a a copy of the article or give us an online reference, so that we can look into the production method used. We will inform you about our assessment within 72 hours.
8. When do I need N-terminal acetylation or C-terminal amidation?
The reason for adding these modifications is to avoid unnatural charges at the ends of the peptide, and to make the peptide more resistant to exopeptidases. We suggest to amidate the C-terminus of N-terminal peptides. The COOH-group then remains uncharged like it would be as part of a polypeptide chain. Analogously, the N-terminus of C-terminal peptides should be acetylated. "Internal" peptides should be modified at both ends.
9. How do you control the high quality of your peptides?
We use high quality reagents and solutions for synthesis, and each synthesis step is monitored.
Together with the peptides you will receive the QC documents: HPLC chromatogram (for purities > 70%) and MALDI electropherogram.
10. What is MALDI-ToF?
MALDI stands for Matrix Assisted Laser Desorption - Time of Flight.
This method determines the mass of molecules.
We can check whether the synthesized peptide has the right mass which means that the sum of the single amino acids is correct or not.
The molecule is ionized, accelerated in an electric field and then collected by a detector.
The time of flight (way from ionizator to collector) correlates with the mass : charge ratio.
11. When will I receive my peptide?
The delivery time depends on the sequence, length, amount and the degree of purification. Unless informed otherwise by us, you can expect a delivery time of 3 weeks for standard non-modified peptides, and 4 weeks for modified peptides.
12. How do I store my peptides?
In general peptides should be stored cool and dry. The peptides are delivered lyophilized. For maximal stability we recommend storing the lyophilised peptide at –20°C. At this temperature peptides should remain stable for several years. Peptides stored on the shelf at room temperature should be stable for a few weeks. Peptides stored at + 4°C should be stable for months.
As a general rule peptides should adjusted to room temperature before opening the vial. The reason is that some peptides might absorb atmospherical humidity when exposed to a "warmer environment".
The peptides are less stable in solution. Just dilute the peptide to the concentration, which is suggested on the Certificate of Analysis (mostly 1-10mg/ml), which you obtain from us. You should use distilled, sterile water for dilution. You can re-lyophilize or freeze the aliquots. In solution they are stable for several hours at room temperature, for several months at -20°C.
Please store solutions of peptides frozen in aliquots. Avoid repeated freeze and thaw cycles. Store the peptide in the dark, if your peptide carries a fluorescent group.
Peptides containing W, M and C are susceptible to oxidation and should be stored under nitrogen or argon. Solutions of these peptides should be degassed and stored at –70°C. We recommend the same procedure for peptides containing Q and N, which are prone to deamination.
13. How do I handle my peptides? What do I do if my peptide refuses to dissolve?
Just dilute the peptide to the concentration which is suggested on the Certificate of Analysis provided by us. You should use distilled, sterile water for dilution. Concentrations between 1-10mg/ml are recommended. At first please follow the special instructions (addition of a special solvent) we mention for certain peptides on the Certificate of Analysis.
The solubility of a peptide always depends on its amino acid composition, and can be difficult, particularly if the peptides are very hydrophobic.
The first solvent of choice is deionised water. Sonication may help to dissolve the peptide. We recommend solubilising a small quantity of peptide to determine optimal solubilisation conditions.
Determination of the net charge of the compound, may be of help:
The charge of each residue of K, R, H, free N-terminal and any additional -NH2 is set at +1; each of D, E and free C-terminal is set at -1.
Basic peptides containing predominantly basic residues (R, K, H; net charge ≥ 1):
Drop by drop add glacial acetic acid (up to 20-30% in volume for problematic sequences)
Acidic peptides containing predominantly acidic residues (D, E; net charge ≤ -1):
Drop by drop add 1% ammonium hydroxide or 10% ammonium bicarbonate.
Hydrophobic (overcrowding of W, F, Y, A, L, I, V, C, M, and Q) or neutral peptides:
Stepwise addition of acetonitrile, isopropanol, DMF or DMSO (from 5 to 50%). Please note that these solvents may have a damaging effect on your experiments.
For peptides with secondary structures, leading to strong tendency to aggregation, it may be necessary to add chaotropic agents such as urea or guanidium chloride.
14. Do you offer Peptide Arrays?
Yes, we do. We are offering a service of multiple peptide synthesis, which can be applied to an order of at least 24 peptides. Purity options are either crude or >70. Peptides should all fall within a range of 8-15 residues. For more information please look at the Peptide Arrays section.
Delivery time is 2-4 weeks depending on the size of the array and required purity.
It is possible to deliver in the peptides in plates. However, for better storage conditions, we always recommend to deliver in single vials. Peptides can also be delivered coated onto the plate wells while we do not provide peptides bound on paper or any other support.
15. What if metabion does not succeed in delivering the requested peptide?
We accept any order for peptides not longer than 30 amino acid residues. If a peptide sequence is not feasible, we will inform you within approx. 1 week from order placement suggesting eventual modifications to the sequence.
It goes without saying that if the sequence cannot synthesized, you will not pay for that specific peptide unless agreed upon otherwise.
For peptide sequences longer than 30 residues, we must see and check the sequence before accepting the order. The acceptance is communicated within 72 hours. Again, if we will not be able to deliver the peptide, the customer will not be requested to pay for it.
In general, synthesis failure for peptides selected from the "standard options portfolio" is less than 5%.