Especially heavy metals show this effect. The exact mechanism of action is still unknown. Data from silver suggest that these ions denature proteins (enzymes) of the target cell or organism by binding to reactive groups resulting in their precipitation and inactivation. Silver inactivates enzymes by reacting with the sulfhydryl groups to form silver sulfides. Silver also reacts with the amino-, carboxyl-, phosphate-, and imidazole-groups and diminish the activities of lactate dehydrogenase and glutathione peroxidase. Bacteria (Gram-positive and Gram-negative) are in general affected by the oligodynamic effect, but they can develop a heavy-metal resistance, or in the case of silver a silver-resistance. Viruses in general are not very sensitive. The toxic effect is fully developed often only after a long time (many hours).
Many infections can spread by doorknobs. Brass doorknobs disinfect themselves in about eight hours, while stainless steel and aluminum knobs never do. Brass doorknobs therefore tend to be more sanitary than stainless or aluminum doorknobs. The effect is important in hospitals, and useful in any building.
Silver is capable of rendering stored drinking water potable for a long period of time (several months). For this reason, water tanks on ships and airplanes are often "silvered".
Silver or silver compounds are used externally in wound and burn treatments.