Colloidal Silver, a Substance That Kills?
Katie Zou, Megan Yan
David Thompson Secondary
Floor Location : M 131 D

Colloidal silver is known as a "dietary supplement" and is claimed to be antibacterial. This particular solution was tested in three wet kitchen sinks. It was questioned whether or not colloidal silver could kill bacteria in wet kitchen sinks or not. To test this unknown substance, three different solutions were made; 5 mL of colloidal silver to 2 mL of distilled water, 7 mL of colloidal silver to 2 mL of distilled water, and 10 mL of colloidal silver to 2 mL of distilled water. The hypothesis was that the stronger the colloidal silver dosage, the more bacteria will be killed. First, bacteria was collected from kitchen sinks using sterile cotton swabs. Then the colloidal silver solutions were wiped on kitchen sinks. Bacteria that came in contact with the colloidal silver solutions was collected. The bacteria samples grew on nutrient agar petri dishes in an incubator. It was soon realized that the dosage of colloidal silver did not matter as bacteria was still being killed with the weaker solution; 5 mL of colloidal silver to 2 mL of distilled water. Bacteria that had not been exposed to colloidal silver and bacteria that had come in contact with colloidal silver were compared to see how the solutions had affected its growth. In conclusion, colloidal silver was able to kill bacteria. The amount of bacteria had decreased when it had come in contact with colloidal silver. More trials will be conducted in the future to achieve more accurate results.