Supplier Page from MedChemExpress for 5-Nitrobarbituric acid
MeOSuc-Ala-Ala-Pro-Val-pNA from MedChemExpress
Omeprazole sodium from MedChemExpress
Pepsin from MedChemExpress
Polyvinyl alcohol (Mw 146000-186000, 99+% hydrolyzed) from MedChemExpress