Aegis Microbe Shield, one of the very few Antimicrobial in the world which you can verify it's treatment's existence. 

Aegis Antimicrobial - Now you can test the efficacy and durability of the Aegis Microbe shield after its treatment to verify its presence even after repeated cleaning. The picture of the ceiling board cut tile demonstrates that the treated ceiling tiles will stain permanently upon reaction with bhemopenol blue. The demonstration on the wall shows a clear distinction on the treated and non treated surface which has the blue mark imprint (mean treated)

Click a picture to see a larger view.