Differential interference contrast (DIC) light micrograph of the freshwater diatom Craticula sp. Craticula belongs to the pennate diatoms (Penna: Latin for feather). The single cells contain wall-bound chloroplasts whose brown colour is caused by the dye fucoxanthin. Here the cell is seen in shell view. The focus is on the inside of the cell with the chloroplasts and two lipid droplets. In the centre of the cell around the nucleus, various Golgi vesicles can be seen. Magnification: x600 at a print width of 10 centimetres.