Comparative Bacteriology Analysis: Particulate vs. Ionic Silver
In this December 2004 analytic lab study by Dr. John W. Roberts, PhD of the Natural-Immunogenics Corporation, the antimicrobial effects of two different forms of colloidal silver were tested. The ‘particulate’ (i.e., metallic) form of colloidal silver was tested against the (free) ‘ionic’ form of colloidal silver.
The bactericidal effects of both forms of silver were compared by treating healthy cultures of two strains of Staphylococcus aureus separately. Each strain was treated separately with the ionic silver and with the particulate/metallic silver. The bacterial strains were also treated separately with equal amounts of HC1 (i.e., hydrochloric acid) added to the silver suspensions.
Results: With or without the HC1 mixture added, the Staphylococcus cultures (both S-1 and S-2) on the plates were virtually eradicated in just four minutes when treated with the ionic silver. But the culture plates treated with the particulate/metallic silver showed only a slight reduction in the bacterial count in the same time-frame. The study authors concluded that the ionic form of colloidal silver is the active, antimicrobial form, while the particulate/metallic form is bactericidal only to the extent that there’s a small component of active silver ion content naturally occurring inside the particulate/metallic suspension. When the ionic silver component is removed, very little bactericidal effect occurs.