I need to know how Phadebas Reagent works to detect amylase (in
saliva). I vaguely remember hearing that in the presence of amylase,
the blue dye in the reagent is released from its bond, hence the
outcome being blue when amylase is present.

Does anyone know the exact details? I've tried googling, but haven't
had much success!

PS: It is forensics related. (The Phadebas Test)

Thanks :)  Any help is much appreciated!