I'ıı measure the glutathione reductase activity of stressed wheats. I need NADPHNa4 for analyses. Supplies firms offer variable prices ranging between 2000E and 3000E (with the same CAS numbers, same purity). The best price was proposed by Calbiochem. But I have never used its products before. I used sigma and it worked very well. But sigma's NADPHNa4 costs more than 3000 E. In short, Are there anyone used Calbiochem? Could you please comment or any advise?