auxanographic method

aux·an·o·graph·ic meth·od

a method for studying bacterial enzymes in which agar is mixed with the material (for example, starch or milk) that is to serve as an indicator of the enzyme action and is inoculated and plated; if the bacteria produce enzymes that digest the admixed material, there will be a zone of clearing in the medium about each colony.
Synonym(s): diffusion method