Fig. 6. Microinjection of ERK2 into the cytosol of NIH 3T3 cells increases the formation of cytosolic lipid droplets. (A) Cells were microinjected with ERK2 (20 ng/µl) and GFP (1 ng/µl), or (as control) GFP alone. The cells were cultured for 2.5 hours and then stained with Oil Red O (no hematoxylin). Bar, 10 µm. (B) BioPix software was used to calculate the total area of red pixels in Oil Red O-stained droplets per cell. Values are mean ± s.d. of 20 microinjected cells from each group (P<0.001, t-test).