How to Read a Certificate of Analysis (COA)
Identity, purity, quantity and the lab that signed it — the four sections of a COA that matter, and the red flags that mean it certifies nothing.
Topic
Lab & Quality
HPLC, mass spectrometry, endotoxin testing, certificates of analysis, and how research-grade material is verified.
7 notes in this topic
What Is HPLC and How Does It Measure Peptide Purity?
HPLC separates a peptide from its impurities on a column and reports the result as a chromatogram. Here is how it works and how to read one on a COA.
Why Third-Party Lab Testing Matters for Research Peptides
A supplier grading its own product is a conflict of interest, not a quality system. What independent testing adds, what it cannot fix, how to read it.
Mass Spectrometry: How a Peptide’s Identity Is Confirmed
Purity tells you how much of a sample is one thing. Mass spectrometry tells you what that thing is. Here is how the identity check works.
Net Peptide Content vs. Purity: Two Numbers, Two Different Questions
A vial can be 99% pure and 75% peptide by weight at the same time. Counter-ions, bound water and how amino-acid analysis resolves the difference.
Endotoxin Testing in Peptide Quality Control
Endotoxin is the contaminant that survives sterilization. How LAL and recombinant assays detect it, and what an endotoxin result on a COA means.
Bacteriostatic Water: What It Is and Why Labs Use It
Bacteriostatic water is sterile water with 0.9% benzyl alcohol. What that preservative does, what it does not do, and how it differs from plain sterile water.
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