Lipid Droplet Staining of Larval Drosophila Oenocytes: A Technique for Assessment of Lipid Droplet Accumulation Under Normal and Stressed Condition Using BODIPY-Based Dye

For lipid droplet staining, incubate the dissected epidermis in fixation buffer, for 30 minutes at room temperature on a rotator, followed by a quick resuspension in 1 milliliter of PBS. Then, wash the samples with three 5-minute washes in 1 milliliter of PBS per wash, to remove any residual fixative.

After the last wash, incubate the epidermal samples with an appropriate lipophilic probe for 30 minutes at room temperature on a rotator. During the incubation, wrap the sample tubes in foil to protect the tissues from light, and wash the samples three times in 1 milliliter of PBS for 10 minutes per wash.

To image the oenocytes, transfer each epidermis sample into 6 microliters of mounting medium on a clean microscope slide. Adjust the orientation of the tissue so that the internal surface containing the oenocytes is touching the bottom of the slide. Gently place a coverslip onto the epidermis, and seal the edges with clear nail polish. When the polish has dried, image the samples on a confocal microscope at a 63X magnification with the appropriate excitation and emission wavelengths.