A Technique to Quantify Fungal Infection in Zebrafish Larvae

Immediately after injection, transfer eight of the larvae into individual 1.7-milliliter tubes, and euthanize them. Prepare 1 milliliter of PBS with ampicillin and kanamycin. Remove as much liquid as possible from the tubes with the larvae. Then, add 90 microliters of the PBS with antibiotics.

Homogenize the larvae in a tissue lyser at 1,800 oscillations per minute for 6 minutes. Then, spin them down at 17,000 times g for 30 seconds. Pipette the homogenized suspension from each tube to the middle of a labeled GMM plate, and spread it using a disposable L-shaped spreader, taking care to avoid spreading against the rim. Incubate the plates upside down at 37 degrees Celsius for 2 to 3 days. Then, count the number of colonies formed.