Zebrafish AB9 cells are a primary fibroblast cell line developed from fin tissue of the AB strain. These cells are commonly used for studies focusing on the biochemical and molecular properties of zebrafish. Cells are grown in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum (FBS) in a humid, 5% CO2-enriched atmosphere at 29°C. Under these conditions, cells passaged 1 in 4 doubled every 72 hours when fed with fresh culture medium at 3-day intervals.