An In Vitro Broth Microdilution Assay for the Screening of Antifungal Compounds

Take a microtiter plate, and add serial dilutions of novel antimicrobial peptides or AMPs — the test compounds.

Designate a subset of wells as growth controls, and add sterile water without the AMPs.

Add a pathogenic fungus suspended in growth media into selected wells.

Add only the media, devoid of the fungus, in a subset of wells designated as blank controls.

Seal the plate and incubate under humid conditions conducive to fungal growth.

Post-incubation, observe the wells under a microscope.

The growth controls appear turbid due to fungal growth in the absence of AMPs. Turbidity across all dilutions of an AMP indicates its ineffectiveness against the fungus.

The blank controls, devoid of fungal growth, appear clear. Compare test wells with the blank controls to confirm the absence of growth, indicating the antifungal activity of AMPs.

The lowest concentration of an AMP that inhibits fungal growth is termed the minimum inhibitory concentration, or MIC.