I want to add resazurin to my media as an anaerobic indicator.
To my understanding, the resazurin is blue when first added to the media, then turns pink after autoclaving, and finally it turns colorless when adding a reducing solution (sulfide in my case). However, I’m having trouble to make the media change from blue to pink. I’ve autoclaved and it’s still blue. My media contains KCl, NH4Cl, KH2PO4, Na2SO4, NaHCO3. I'll add sulfide and other metals after autoclaving.
Should I flush my media before autoclaving? what controls that first reduction step? Heat alone seems not enough to reduce the resazurin. Should I add another reductant in addition to sulfide?
I’d appreciate your comments and insights on this.