How we test every batch
Every batch we sell is independently purity-tested by Janoshik using HPLC before it is released for sale.
From batch to your lab, in four steps
No batch goes on sale until it has passed independent purity testing.
Batch received
A new production batch arrives from our manufacturing partner.
Sample sent
A sample from the batch is sent to Janoshik, an independent analytical laboratory.
HPLC purity test
The sample is analysed by HPLC to measure its analytical purity.
Released for sale
Only batches that meet our purity standard are released to the store.
What HPLC testing tells us
High-performance liquid chromatography (HPLC) separates the components of a sample as it passes through a column. Each component reaches the detector at a different time and shows up as a peak. The size of the main peak compared with all peaks gives the sample’s analytical purity, expressed as a percentage.
It is the standard method used across the peptide industry to check how pure a compound is.
- Measures analytical purity of the tested sample
- Performed by an independent laboratory, not by us
- Carried out on every batch before release
Blends, independence and the scope of testing
Blend products
Blends such as GLOW and KLOW contain several peptides in one vial. Measuring each component in a mixed sample is more complex than testing a single compound, so the testing approach for blends can differ from single-peptide products.
Independent, not in-house
We do not test our own products. Testing is carried out by Janoshik, an independent analytical laboratory, so results come from a third party with no stake in the outcome.
Scope of testing
Test results relate only to the specific sample and batch tested, and only to the parameter measured: analytical purity by HPLC. They are not a guarantee for other batches and do not imply that other parameters have been tested.
Testing questions
Who tests your products?
Every batch is tested by Janoshik, an independent analytical laboratory. We do not test our own products, so results come from a third party.
What does the testing measure?
Testing measures the analytical purity of the batch using HPLC (high-performance liquid chromatography).
Is every batch tested?
Yes. Each batch is purity-tested before it is released for sale. Batches are not released until testing is complete.
How are blends tested?
Blends contain more than one peptide, so the testing approach can differ from single-compound products. Results for blends should be read according to the scope of the test performed.
Are your products for human use?
No. All products are supplied strictly for in vitro laboratory research. They are not for human or animal use, and not for diagnostic, therapeutic or medical purposes.
Questions about a batch?
Email us with the product name and your order number.
All products sold by Sterling Peptides Ltd are intended strictly for laboratory research and analytical purposes only. They are not intended for human consumption, veterinary, medical, therapeutic, diagnostic or clinical use. Purchasers are responsible for determining the suitability of these materials for their laboratory applications. See also our Research Use Disclaimer.