Determining the Bacterial Cytotoxicity of Silver Nanomaterials: Scientific Operating Procedure Series: Toxicity (T)
ERDC Vicksburg United States
Pagination or Media Count:
Materials at the nanoscale have physiochemical properties that differ from their bulk material. Consequently, the growing use of nanomaterials in industrial and consumer products raise important questions about their environmental fate. The potential cytotoxic effects on microbial communities is an important safety and material life cycle consideration, as microorganisms play a vital role in environmental nutrient cycling, influence health, and disease of plants and animals, including humans. This Scientific Operating Procedure SOP describes a set of methods to determine the cytotoxic effects of nanomaterials on bacteria. Initial growth effects, including minimal inhibitory concentration MIC, can be monitored by a standardized microplate broth dilution assay when the nanomaterials stay suspended and do not inhibit optical density OD measurements. When these requirements are not met, a solid agar dilution plate MIC assay can be used whereby toxicity is determined by colony counts on agar plates. A standard minimum bactericidal concentration MBC assay is also detailed and can elucidated the mode of action of nanomaterials that have an MIC.