Resources

Reference notes

Written for people evaluating a supplier, not for search engines. Everything here is about the documents and the chemistry — nothing on this site describes use in a living subject.

• August 12, 2026 · 7 min read

  How to read a peptide certificate of analysis

  A certificate is only useful if you know which numbers are load-bearing and which are decoration. Here is the whole document, line by line.

• July 28, 2026 · 5 min read

  Why 99% purity, on its own, tells you nothing

  Purity is a ratio, not a quantity — and it can be perfectly true about the wrong molecule.

• July 9, 2026 · 5 min read

  Endotoxin: the contaminant that produces a plausible result

  Most contamination adds noise. This one adds signal — which is considerably worse.

• June 20, 2026 · 6 min read

  Storing and reconstituting lyophilized peptides

  The chemistry is straightforward. Most of the loss happens after the vial is opened.

• June 2, 2026 · 4 min read

  Lot numbers, and what makes one real

  A lot number is a promise that a certificate can be matched to a vial. Most of the time nobody checks whether the promise resolves.

Rensa Research supplies research chemicals for in-vitro laboratory use. Nothing on these pages is medical, veterinary or dosing guidance.