Practical Resources
Guides
Practical guides for understanding testing documentation, evaluating RUO companies, and interpreting research. Written for researchers who want to go beyond the headline claims.
Evaluating Companies
How to Evaluate an RUO Peptide Supplier
A practical framework for assessing research-use-only companies before purchasing. Covers COAs, testing documentation, batch traceability, and RUO positioning.
What to Look for in a Certificate of Analysis
Not all COAs are equal. This guide explains what a useful COA contains, what common omissions mean, and how to match a certificate to a specific lot.
Understanding Testing
HPLC vs. LC-MS: What Each Test Actually Tells You
HPLC measures purity. LC-MS confirms identity. Both matter — but they answer different questions. Here is how to read each type of result.
What "99% Purity" Actually Means
The headline purity figure is the most commonly cited number in RUO marketing. Here is what it measures, what it does not measure, and why net peptide content is often more relevant.
Endotoxin and Sterility Testing: Why It Matters for Research
Microbiological testing goes beyond purity. This guide explains what endotoxin and sterility testing measure and why their presence — or absence — in a COA is significant.
Research Context
What Research-Use-Only Actually Means
RUO is a legal and regulatory designation, not just a disclaimer. This guide explains what it means, what it requires, and why it matters for researchers.
Looking for company-specific information?
The RUO Company Directory compares every reviewed company across six criteria.