MDH stains LDs.

<p>(A) MDH staining patterns in HepG2 cells mimicked cytosolic LDs. Fluorescence emission between 420–480 nm resulted in a high contrast, low background staining of round spots in HepG2 (<i>top</i>; 405 nm excitation). In contrast, emission between 550–650 nm generated images retaining the round spots, but with diffusive background stains (<i>bottom</i>). (B) HepG2 cells were transiently cotransfected with TagRFP-ADRP (<i>colored red</i>) and EGFP-tubulin (<i>colored green</i>), and stained with MDH (<i>colored blue</i>). ADRP signals surrounded the MDH spots (Inset; magnified image of the white dotted square region), indicating that MDH patterns are indeed LDs. MDH can be combined with the use of green and red fluorophores, as evidence by the separate MDH/ADRP/tubulin images. (c) MDH specifically stained the LDs in 3T3-L1 cells before and after differentiation. <i>Top:</i> undifferentiated. <i>Bottom:</i> ten days after differentiation, showing the expected increase in average LD size. Scale bars, 10 µm.