What a 27% rise in coupling-reagent prices does to a 15 mg vial
Follow the resin, not the catalogue.
Peptide synthesis
Page 12 of 13 of this archive, newest first.
Shanghai export categories for peptide intermediates were quietly renamed
Follow the resin, not the catalogue.
What a 25% rise in coupling-reagent prices does to a 10 mg vial
Follow the resin, not the catalogue.
Qingdao export categories for peptide intermediates were quietly renamed
Follow the resin, not the catalogue.
What a 23% rise in coupling-reagent prices does to a 15 mg vial
Follow the resin, not the catalogue.
The specification sheet says 500,000. The report says conforms.
Calibration drift is real, unremarkable, and the reason serious laboratories run internal standards.
Tianjin export categories for peptide intermediates were quietly renamed
Follow the resin, not the catalogue.
Quadrupole, time-of-flight, orbital trap: what each class can and cannot see
Every instrument specification quoted in an advertisement is a best case obtained on a calibration mixture, not on a submitted vial.
What high resolution actually buys you
Parts per million sound impressive until they are converted into daltons at the molecular weight of the thing being measured.
Qingdao export categories for peptide intermediates were quietly renamed
Follow the resin, not the catalogue.
What a 7% rise in coupling-reagent prices does to a 5 mg vial
Follow the resin, not the catalogue.
Leucine, isoleucine, and a difference no balance can measure
Deamidation adds 0.98 daltons. On a low-resolution instrument at incretin molecular weights, that is inside the noise.
Resolving power and mass accuracy are two different specifications
Every instrument specification quoted in an advertisement is a best case obtained on a calibration mixture, not on a submitted vial.
What a 41% rise in coupling-reagent prices does to a 10 mg vial
Follow the resin, not the catalogue.
Deamidation, oxidation, and the two shifts worth memorising
What would be needed to catch each of these, and what it would cost.
What “LC-MS: conforms” tells a reader, which is almost nothing
A short audit procedure, usable by anyone holding a certificate and a calculator.
Suzhou export categories for peptide intermediates were quietly renamed
Follow the resin, not the catalogue.
D-amino acids are invisible to mass spectrometry, and that is the whole problem
Stereochemical inversion changes the molecule, changes its biology, and changes its mass by exactly nothing.
What a 23% rise in coupling-reagent prices does to a 10 mg vial
Follow the resin, not the catalogue.
What a 39% rise in coupling-reagent prices does to a 15 mg vial
Follow the resin, not the catalogue.