fbpx

Why Aren’t Your Peptides 100% Pure?

Wonder why some of our products are not always 100% pure?

Due to technological limitations, it is virtually impossible to synthesize, wash and elute a batch of peptides that are 100% pure (ie. every peptide in the batch is identical and there are no chemical impurities whatsoever). Fortunately, there are well-established thresholds set for different applications. Choosing the minimum purity value is based on a cost-benefit analysis keeping in mind the intended application.

For instance, peptides batches that are determined to have a purity value of 95% are pure enough for NMR spectroscopy, quantitative receptor-ligand interaction studies, in vitro bioassays, and a variety of other high-precision scientific assays—yet we won’t even release 95% pure peptides for sale. We simply throw them in the garbage, write-off the loss, and commission a new batch with higher purity.

We only sell clinical grade peptides, no exceptions.

Peptide Purity Comparison Chart

If My Peptide Is 99% Pure, What Is The Other 1%?

Because synthetic peptides are built amino acid by amino acid, the most common impurity is simply a shorter, truncated peptide that didn’t get built to completion. In some cases, these truncated peptides may retain partial function, yet in most cases they simply lose their biological activity. 

Regardless, the crucial point to consider is that when peptides are built using high quality reagents following the guidelines of Good Manufacturing Practices (GMP), the resulting impurities are not biological contaminants or harsh solvents, so they don’t raise any safety concerns. Thus, a more relevant designation would be to consider a 99% pure peptide as “99% active and 1% inactive.” 

The strictest guidelines for peptide purity are those that are set for clinical trials, since both safety and biological specificity are of the utmost importance when rigorously evaluating biological activity in humans. For clinical trials sponsored by the National Institutes of Health, synthetic peptides generally need to be ≥98% pure. The vast majority of our current peptide batches are ≥99% pure, thus exceeding the most discriminating threshold set for human research studies.

How Sensitive Is Your Quality Control?

We contract with an accredited diagnostics lab, MZBiolabs, for third-party quality control testing of every single batch of our peptides. MZBiolabs excels at mass spectrometer and high-performance liquid chromatography using a flexible set of high-end instrumentation: linear ion trap, 3-D trap, ESI and APCI sources, UV/fluorescence detectors, nano flow columns, etc.

This extensive range of equipment permits exceptionally sensitive analyses that can detect the smallest of changes to molecules; for example, when the amino acid Glutamine becomes “deamidated”—which can occur as the result of a synthesis error or spontaneously during degradation—it causes a tiny mass shift that will be missed by most standard mass spectrometer setups offered by cheaper third-party labs.

In the world of peptides, it’s true what they say: you get what you pay for. Is it really worth saving a few dollars to get junk peptides that were tested on old equipment in a sketchy basement by individuals with no professional accreditation? Of course not.

How Are Your Peptides Shipped?

We use industry standard shipping for lyophilized peptides, and packages are sent out Monday through Wednesday or Thursday (depending on destination in continental US) to avoid any potential weekend delays.

Lyophilized peptides are shipped at ambient temperature by all major research chemical supply companies, including Sigma Aldrich, Thermo Fischer, Cayman Chemical, etc, except in circumstances where particular peptides are unusually temperature sensitive. 

Importantly, all of the synthetic peptides that we carry are stable in a lyophilized sate at ambient temperature for days to weeks. Moreover, given that most of our peptide batches are assayed to be ≥99% pure, their stability is increased relative to other lower purity peptides offered for sale elsewhere.

This is because peptide-related impurities (eg. spontaneously deamidated peptides) and non-peptide-related impurities (eg. TFA salts) can decrease the physical stability of synthetic peptides. Thus, our high threshold for peptide purity also improves stability during shipping and handling. Nevertheless, it is obviously recommended to place your peptides in a freezer upon delivery and to avoid subsequent freeze-thaw cycles.

Some of our proven pure peptides:

By Using This Website You Agree To Our Terms Of Service

FDA Disclaimer • Copyright © • An UMBRELLA Company