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Five analytical methods. Every batch. Here’s what each one tests for and what we accept.
Every lot is run through five independent analytical tests before release. Below is what each method measures and what we require to ship.
What it measures: Reverse-phase high-performance liquid chromatography separates the target peptide from impurities, breakdown products, and process-related residuals. The detector quantifies the area under the target peak relative to total peak area.
Result format: A purity percentage (e.g., 99.34%). Internal release threshold is 98% minimum. Most lots come in at 99%+.
Why it matters: Purity is the single most important assay for a research-grade peptide. A peak in the right place isn’t enough — it has to be clean of side products from synthesis.
What it measures: Liquid chromatography-mass spectrometry confirms that the molecule is, in fact, the molecule on the label. The mass spectrometer measures the intact molecular weight of the eluting peak and compares it to the theoretical mass of the target sequence.
Result format: An observed m/z value compared to the theoretical mass. A match within mass tolerance confirms identity.
Why it matters: HPLC tells you the peak is pure; LC-MS tells you the peak is the right molecule.
What it measures: A sample is incubated in growth media under USP <71> conditions for 14 days and inspected for microbial or fungal growth.
Result format: Pass / no growth detected.
Why it matters: Sterile-fill research material that will be reconstituted for in-vitro work cannot be a contamination source.
What it measures: Limulus amebocyte lysate gel-clot or kinetic-chromogenic assay quantifies bacterial endotoxin (lipopolysaccharide) levels in the sample.
Result format: Endotoxin units per milligram, with a defined upper limit.
Why it matters: Even a sterile sample can carry endotoxin from gram-negative bacterial debris. For parenteral-route research workflows, endotoxin load matters.
What it documents: Each batch is assigned a unique lot number that is photo-logged at receipt, weight-verified, and tied to the signed COA. The lot number is printed on every vial label.
Why it matters: If a question ever surfaces about a specific shipment, we can trace it back to the original analytical workup, the original sample, and the original date.
All five test results are published, lot-stamped, on the COA Library. The lab that runs the methods is described on Lab Partner.
All products offered by Elixser Peptides are intended strictly for laboratory research purposes and are not for human or animal consumption. These materials are designed for in vitro scientific study only and should be handled exclusively by qualified professionals within controlled laboratory settings.
By purchasing from Elixser Peptides, you acknowledge and agree to use all products in accordance with applicable laws, regulations, and ethical research standards.