Protocol to induce de novo lipid droplets in Saccharomyces cerevisiae

The mechanisms underlying lipid droplet (LD) biogenesis in the endoplasmic reticulum are not completely understood. Here, we present a protocol for inducing de novo LDs containing either triacylglycerol (TAG) or sterol esters (SE) in Saccharomyces cerevisiae. We describe steps for generating conditional yeast mutants by performing gene knockout and introducing galactose-inducible promoter to produce TAG- or SE-containing LDs. We detail the strategy to generate fluorescent LD marker protein to visualize newly formed droplets by fluorescence microscopy.