For GSSG measurement, 2-vinylpyridine (Sigma-Aldrich) was added before the enzymatic reactions to remove reduced glutathione
Freeze-thaw cycling is especially destructive to peptides each cycle forms ice crystals that physically shear the molecule, so even one accidental freeze can tank a vial
Jos A, Trujillo-Hernandez L, Bariat TA, Enders LC, Strader J-P, Reichheld, Christophe Belin (2020) A glutathione-dependent control of the indole butyric acid pathway supports Arabidopsis root system adaptation to phosphate deprivation
Dropper bottle for easy application
They're legally available when the brand-name versions are on the FDA drug shortage list
2A) did not provide a clear discrimination among most of the samples except for those obtained from S