the source for all peptides for your research


Custom Peptides

Peptides play a key role in many biochemical and immunological assays, including enzyme-substrate studies, blocking and competition assays, epitope mapping, T cell stimulation and many more. We bring you a custom peptide synthesis service that recognizes the importance of high quality reagents for these applications, delivered to you with a fast turnaround time and at excellent value.

Custom Peptide Synthesis Product Range

Our standard peptide synthesis service includes the following purities and quantities of peptide. Contact us if you require lower grade purity or larger amounts, we can also supply in gram quantities.



>70%, >75%, >80%, >85%, >90%, >95%, >98%


1-4 mg, 5-9 mg, 10-14 mg, 15-19 mg, 20-24 mg, 25-29 mg, 50-59 mg

Typical dispatch time

>70% and >75% purity, approximately 3 weeks
>80% to >98% purity, approximately 4 weeks


If your requirements fall outside the range of scales, purities listed above, contact us for a special quotation tailored to your needs.


Alongside standard custom peptide synthesis and a wide range of modification options, we offer high-throughput synthesis of custom peptide libraries. Peptide libraries can be used to investigate immune responses in detail or can provide an efficient method of screening the activity of a large number of peptides in an application.


Key publication:


Epitope map of Israeli Acute Paralysis Virus could help save declining honey bees


Ren J. et al(2014)“Assembly of Recombinant Israeli Acute Paralysis Virus Capsids.” Plos One doi:10.1371/journal.pone.0105943.g003

Figure 1. Linear antibody epitope map of 4 monoclonal antibodies to IAPV VP2 on an overlapping peptide library.

Summary: Israeli Acute Paralysis Virus (IAPV) has been implicated in the worldwide decline of honey  bees. Ren et al studied the molecular protein biochemistry of how IAPV expresses and assembles into virus particles in insect cells. Monoclonal antibodies developed by Ren et al. specific to IAPV capsid proteins and an understanding of the highly specific epitopes they recognize as determined by Ren et al. could contribute to diagnostic tests to detect this bee pathogen. Such tests could play an important role in developing a better understanding of the epidemiology of IAPV in the honey bee population. Peptides for epitope mapping for this study were custom synthesized by thinkpeptides.


Praise for thinkpeptides from

Annelie Hellvard
The Gade Institute, University of Bergen, Norway

“We have had nothing but good experiences using peptides synthesized by thinkpeptides. Since we started working with them in 2009 there have been no issues whatsoever, and the peptides were a big part of a recent publication in the Journal of Immunology [PubMedID:20488785].  I am always surprised by how fast quotes are delivered and questions are answered – the customer service is excellent. We feel like they have a very good product for decent price.”



Modified Peptides

Our extensive range of custom peptide modifications includes, but is not limited to those in the table below. Contact us if you need a modification that is not on the list.


7-Methoxycoumarin Acetic Acid
Myristic Acid


7-Amino 4-methyl coumaride



Non-standard residues

D-amino acidsN-methyl amino acids

Other modifications



Design and Application Support from ProImmune’s Experts

Our technical and applications support team can offer advice on library design, peptide solubilization, experimental set-up, and analysis. Relating to design, we can advise on the best overlap or offset of peptides to be used in your target application, and then using your full-length protein sequence, we can generate the list of peptides for your library.


Custom Peptide Libraries

Synthetic custom peptides offer a rational, scaleable and ever more affordable approach for exploring protein-protein interactions or even more complex phenomena such as immune responses directed against specific epitopes. As the use of such peptides increases it becomes ever more important to consider all relevant factors when designing large peptide libraries for synthesis. Our applications scientists have the experience to help you get the peptide design right for your project. Our approach is to offer you flexible, scaleable synthesis wherever you are.




Figure 2. Schematic representation of the different strategies in constructing peptide libraries for sequence optimization. The presumed essential positions are enclosed in the dotted box. A. Alanine Scanning Library. Alanine is systematically substituted into each amino acid position in the identified epitope. This strategy identifies the amino acids in the native sequence that are essential for activity. Substitution of an essential amino acid results in a reduction in peptide activity, and the degree of reduction in activity is usually taken as a relative measure of the importance of the amino acid being substituted. B. Truncation Library. This strategy determines the minimum length required for optimum peptide activity by generating a set of peptides with systematic truncation of the flanking residues. If the essential amino acids are known, the direction of truncation can be selected around them, as opposed to systematic truncation from both ends of the peptide sequence. C. Random Library. Selected residues in the peptide sequence (wobbles) are simultaneously substituted with a mixture of all 20 amino acids, or a mixture of specific amino acids. In practise, this strategy is usually used for preliminary identification of a group of active sequences that can then be re-synthesized to validate the initial results. D. Positional Scanning Library. A selected position or positions in a peptide sequence are each systematically replaced with different amino acids in order to determine the preferred amino acid residues at these positions, measured by corresponding increases in activity.


Prospector PEPscreen® Peptide Libraries with High Average Purity

Peptide Libraries deliver highly attractive prices and exacting 100% LC-MS quality control. Prospector PEPscreen® libraries offer the cost advantage of crude synthesis, whilst achieving high average purity. The average purity of 10mers is ~86%, the average purity of 15mers is ~73% and the average purity of 20mers is ~61%. The features of Prospector PEPscreen® Libraries make them an ideal product for high throughput epitope discovery applications, giving you the comfort of comprehensive QC so you know absolutely what you are working with.

Unlike other commercial peptide libraries available, there are no hidden set-up charges. A single price is charged per peptide, and the order size starts at only 24 peptides. Prospector PEPscreen®: Custom Peptide Libraries accommodate peptides from 6-20 amino acids.

Prospector® libraries are perfect for researchers using large numbers of peptides in applications such as CD4+ and CD8+ T cell epitope mapping, B cell epitope mapping, ELISPOT, intracellular cytokine staining, protein-protein interactions, receptor-ligand studies and cellular assays.









Prospector PEPscreen®


0.5-2 mg

100% MS or
100% LC-MS

2-3 weeks <500


Quality Control

The power of high throughput MS analysis

For the Prospector PEPscreen® product, MALDI-TOF Mass Spectrometry (MS) is performed on 100% of samples.  Each peptide must meet both the MS analysis and the final gross weight criteria to pass quality control (QC).  For a peptide to pass the MS criterion the desired molecular mass must be one of the three major ions.  Peptides that fail QC by MS will be remade once.  Subsequent failed peptides are supplied as part of the order, and are labeled accordingly in the paperwork, allowing the user to decide whether or not to include the peptide in their studies.

We also offer the option of including LC-MS analysis for PEPscreen® peptides.


Prospector PEPscreen® Product Format

Prospector PEPscreen® peptides are dried as a thin film at the bottom of individual tubes. This is to prevent the peptide from smearing throughout the inside of the tube during transit, which can make resuspension in small volumes difficult. Tubes are individually capped and arranged in a standard 8 x 12 tube array for compatibility with high throughput assays. This format also allows the flexibility to select only the tubes of peptides of interest and rearrange them into a convenient assay format. Each tube is clearly labeled in case the tubes are accidentally mixed.
Minimum order size 24 peptides.