American Peptides

HPLC and mass spec measure chemistry. Endotoxins are biological remnants — invisible to both. A vial can be 99% pure and still loaded with them.

Endotoxins are biologically active. They trigger immune responses, inflammation, and cytokine release on their own — corrupting research data before the experiment begins.

Purity tests don't culture for bacteria, fungi, or yeast. Live contamination can grow in a vial that "passed" purity testing.

Microbial growth introduces unknown variables into every experiment. We test every batch against USP sterility standards.

Heavy metals are inorganic. HPLC and mass spec are blind to them entirely. They require a separate test (ICP-MS) most suppliers skip.

Heavy metals accumulate in biological tissue and produce confounding effects in long-term studies. We screen for all four primary contaminants on every batch.

Spot-checking one vial per run is industry standard. We pull multiple samples per batch and test against the same reference every time.

Reproducibility is the foundation of legitimate research. If batches drift, your data drifts with them.