How to handle your PepMix™ - User Guidelines

Published on 20/03/2025

With a portfolio of over 500 products, JPT’s PepMix™ Peptide Pool Catalog remains the largest on the market. We offer a wide variety of peptide pools tailored for immune monitoring, cellular immune response profiling, or T cell epitope identification, providing unparalleled resources for cutting-edge research in immunotherapy and vaccine development, immune monitoring and gene therapy.

But have you ever wondered what you need to know about handling, storing and using our peptide pools?

What are technical specifications?

We consider technical specifications to be anything outside the standard PepMix™ peptide pool that you have control over to adjust, select and modify:

Select the right quantities: Our standard PepMix™ Peptide Pool contain 25µg (or 15 nmol) per peptide. However, in some cases we also offer larger quantities (200µg, or 120 nmol of each peptide). Our control pools on the other hand come as 15nmol/peptide, due to varying peptide lengths in the pool. Please refer to the product datasheet on the product page or select the appropriate quantity when customizing your own peptide pool. Our technical support team will be happy to help.
Choose the right purity: research grade (crude with guarantee), development grade (>70% HPLC/MS), or trial grade (>90% HPLC/MS); we guarantee each peptide to be present at the minimum given purity level, also known as individual purity.
How many peptides are in a mix: this depends on the length of the antigen. A mix can contain between 10 and several 100s of peptides. Due to solubility and stability we recommend a maximum of 150 peptides in a pool.
What about sequence length & overlap: Outside of our standard 15mer length and 11mer overlap, we can adjust it to your requirements.
PepMix™ as subpools: Often a peptide pool does not need to cover an entire antigen to elicit a strong immune response in an assay, so we offer an economical smaller version of the PepMix™ peptide pool.
Design your own layout!
Modifications: any are possible!

Find out more about some specifications below:

What about peptide storage and stability?

About 20% of all peptides show a limited shelf stability, while most peptides are stable for years. There are some amino acids that might render a peptide potentially unstable.

So, how do you recognize and handle potentially unstable peptides?

In general, peptide stability over time increases if peptides are stored freeze-dried, if possible, at -20° or lower. You can directly order small freeze-dried aliquots from us. If you need to store peptides in solution, avoid repeated freeze-thaw cycles and prepare small aliquots! For your custom PepMix™ Peptide Pools take advantage of our stability testing service, and we test the peptide’s stability of your aliquots over a few months.

How to dissolve peptides?

Did you ever have a problem dissolving a peptide or having limited solvent choices?

Peptide solubility is a crucial factor for in vivo availability and assay robustness. Lack of solubility will lead to a lower concentration in solution and therefore decreased activity and even possibly false negative results. The stock solution can be diluted for use in your assay. Based on literature, we recommend a maximum DMSO concentration below 1% (v/v) in cellular assays.

However, performing solubility tests yourself can be time and material consuming. We offer a solubility testing service based on the Turbidmetric Solubility Assay (TSA) for your custom PepMix™ Peptide Pools. We provide you with a complete dissolution profile of your peptides, helping you save time, money, and material.

What does purity mean at JPT?

Oftentimes, peptide vendors will list an “average” or “mean” purity for peptide pools or libraries. This could be misleading since some individual peptides in the pools might have a very low purity (or are even missing), while this is compensated by peptides having a high purity creating the average.

At JPT, for peptide pools offered with a specific purity (e.g. >70% or > 90%), we always analyze each peptide and provide the guaranteed purity for each individual peptide. We assure that each peptide is at or above the target purity specification!

Moreover, we guarantee and communicate the presence of EACH peptide in the pool using our validated pooling protocol!

Contact Us!

Our team of experts is always here to support your research needs and also check the resources on our webpage and the PepMix™ application protocol. Do you know that we have been part of the ELISpot handbook with our chapter on peptides.