Fig. 3. GFP accumulation in the ER of P. tricornutum expressing a BiP:GFP fusion protein. (A) Images from a confocal laser scanning microscope. Top-left: green GFP fluorescence; Top-right: red chlorophyll fluorescence indicating the location of the plastid; bottom-right: overlay of the fluorescent images. (B) Reconstruction of 3D images from a series of confocal fluorescence micrographs of GFP fluorescence (top), and combined GFP and chlorophyll fluorescence (bottom). GFP is primarily located in cytosolic ER strands and the nuclear envelope. P, plastid; N, nucleus. Bars, 2 µm.