Automated screen of 14 siRNAs after 72 h solid-phase transfection knockdown. (a) Transmitted light image of one Petri dish with the 32 siRNA spots (left), where each siRNAs transfection mix is placed in the culture dish following a definite arrangement, see Table S2 for further details (right). (b) Morphological features of the Golgi apparatus scoring tubularity, diffuseness, fragmentation, and condensation for COPB1 (n = 26), COPB2 (n = 34), COPG1(n = 88) in comparison to negative control (Neg9, n = 305). Values of each feature are normalized with respect to the mean of the control. During the light microscopy workflow, cells transfected with COP siRNAs display a phenotype that can be identified because of their high value in diffuseness. As an example, we selected one cell of each COP-related siRNA (black triangles), to display in (c) the final result of the correlative experiment. (c) Selected correlated cells control (Neg9), COPB1, COPB2, and COPG1 (top to bottom): overview merged fluorescent, reflected light image and image of the siRNA spot (LM merged overview), the fluorescent image of a selected cell (LM selection target cell), a cross-section through the selected cell in the region of the Golgi apparatus acquired automatically with the FIB-SEM (EM single slice from FIB-SEM volume) and a zoom into the Golgi region (EM Golgi region). Three corner siRNA spots are highlighted with fluorescent gelatine (Alexa 594), shown as a red outline, whereas the last corner siRNA spot is highlighted with gelatine (Oregon green) shown as a green outline to make the orientation always recognizable. Scale bars: (c) left to right, 100, 10, 1, 1 µm.