Three Tests US Buyers Routinely Treat as One
Three terms get swapped around as though they were synonyms, and they measure three different things.
support@exolabz.co
How research peptide identity and purity are verified, and how to read the supporting analytical documentation.
Three terms get swapped around as though they were synonyms, and they measure three different things.
A certificate prints a measured mass beside a calculated one and the two agree to a couple of decimal places. Is that a good result?
Here is a discrepancy worth pausing over: a report where the measured figure and a database figure sit about one dalton apart. That is the size of a real modification.
Set a reversed-phase method to one fixed acetonitrile percentage, inject a peptide, and the run usually fails in one of two ways.
Two numbers on a data package can both be right and still disagree. A chromatogram says the material is 98 percent of a single species…
Read a certificate showing high chromatographic purity and a confirmed mass, and it is easy to assume the whole contents of the vial have been accounted for. They have not.
Send one batch to two laboratories and you may get back two chromatograms that differ by a single small peak. The instinct is to decide which laboratory made a mistake.
Treating 98.4 percent and 98.7 percent as meaningfully different values is nearly always an error.
"Not detected" is one of the least informative phrases a report can contain. Read strictly, it means: not seen by this particular method, at this wavelength, at this sample load…
Take a 43-residue protein, push it through a 100 angstrom C18 column on a gradient somebody wrote for a different molecule…
Two certificates arrive for what is nominally the same compound. One reads 98.4%, the other 98.9%, and the order goes to the second. That choice was made on noise.
A mass tells you which molecule, never how much of it Begin with the limitation, because it governs everything downstream.
Shop by research area
Most requested
Guides & help
5.0 from 25 customer reviewssupport@exolabz.coReplies in about an hour
Shop by research area All 44 compounds →
Most requested
Start here
Research libraryMethods, analytics and lab practice articlesResearch peptides in the USASourcing, testing and delivery explainedChoosing a supplierWhat to check before you orderPeptide glossaryTerms from HPLC to lyophilisationHelp centre
Your account
Programs
BPC-157 10mg
NAD+ 1000mg
MOTS-c 10mg
Selank 10mg