FAQ: PepTrack™ Peptide Libraries

Please refer to the corresponding frequently asked questions (FAQs) below.
If you can not find the question you are looking for, please contact our customer support team:

Which PepTrack™ option is best for my application?

For screening and discovery approaches, one of the most economical options Fast Track or Research Track might be best suited.
Depending on the goal of the experiments, we may recommend a combination with full analytical coverage by LC-MS and/or an increased purity level (i.e. main product = target peptide).
For all immune monitoring applications and assessment of vaccination trials, we recommend PepTrack™ (Discovery Track & Trial Track) options with guaranteed purity levels and full analytical coverage.
Please contact our customer support for more details at

Why are JPT’s peptide libraries superior to those of other peptide vendors?

JPT maintains an DIN ISO 9001: 2015 certified Quality Management System since many years and was successfully audited to fully comply with Good Clinical Laboratory Practices (GCLP) for its custom peptide services to be used in clinical T-cell assays.
Together with its governmental-, NGO- and industrial partners, JPT designs peptide synthesis and purification protocols that avoid formation and presence of false positive failure sequences and contaminants in ELISpot, ICS and other T-cell assays.
In addition, JPT ensures that no toxic contaminants will be present in its peptide preparation. Stringent documentation avoids presence of epitopes from foreign antigens and cross contaminations.
JPT provides exact purity information for all peptides that are analyzed. QC is performed by QUANTITATIVE LC-MS and NOT by QUALITATIVE MALDI-MS.
JPT offers QUANTITATIVE QC on all peptides that are synthesized.
JPT does not offer peptide purities based on misleading terms such as "average purity".
All peptides will be produced at JPT’s main laboratories in Germany.
JPT does not sell or distribute peptides from any other vendor. JPT’s raw material vendors are audited on a regular basis for reliability.
Final peptides can be traced back to the level of raw incredients.
Related documents are archieved for 10 years.

How do I solubilize my peptide library?

The solubility of peptides greatly depends on its primary and secondary structure and on the nature of modifications made.
Many peptides are soluble in aqueous solution, basic peptides in 10% acetic acid and and acidic peptides in aqueous ammonia or 10% ammonium bicarbonate solution.
Unfortunately, final solubility is hardly to predict.
Therefore, for PepTrack™ libraries we suggest to apply DMSO as an organic solvent which enables complete dissolution of most peptides.
In order to dissolve your peptides, apply the minimal amount of DMSO to dissolve your peptide and slowly add aqueous buffer or medium until the final concentration is reached. 'Please note that DMSO can oxidize peptides upon storage and has cell toxic properties when used in concentrations at elevated concentrations.

What are the best storage conditions and how stable are the peptides?

Peptides will generally be provided lyophilized as white fluffy materials which has been proven to be the best choice to avoid premature decomposition.
Ideal storage conditions are:

  • storage at –20°C or colder in a dry environment.
  • avoidance of repeated freeze-thaw-cycles. -try to avoid storage of aliquotes in solution, instead:
  • if storage in solution can not be avoided, store at –20°C and use sterile buffers ad slightly acidic pH.

How are Peptrack™ libraries delivered?

Fast Track:
freeze dried in 96 well microplates with rubber mat
Research Track:
freeze dried in 96-vial micronic racks (96 individual tubes) closed with individual rubber caps 
Discovery Track:
freeze dried in 96-vial micronic racks (96 individual tubes) closed with individual rubber caps or 4ml plastic tubes with screw cap
Trial Track:
freeze dried in 96-vial micronic racks (96 individual tubes) closed with individual rubber caps or 4ml plastic tubes with screw cap

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