[14C]Acetate Incorporation Assay

[1-¹⁴C]Acetic acid, sodium salt, was purchased from PerkinElmer. Suspension culture cells were labeled 1 week after subculturing with a cell weight of approximately 40 mg. Cells were labeled by incubating in 0.2 μCi of [¹⁴C]acetate for 20 min at room temperature with constant shaking. Cells were subsequently rinsed three times with water. Total lipids were extracted with 500 μL of methanol:chloroform:formic acid (20:10:1, v/v). The organic phase was then extracted with 370 μL of 1 m KCl and 0.2 m H₃PO₄ and suspended in 2 mL of Ultima Gold liquid scintillation cocktail (PerkinElmer). The incorporated radioactivity was measured in cpm with a scintillation counter (Packard BioScience).