English: (A) shows a light micrograph of H. polymorpha cells that are grown in a methanol-limited chemostat culture. In the cells the cuboid inclusions that represent peroxisomes are evident. (B) shows an electron micrograph of the same organism, grown in batch culture on glucose. These cells contain only a single small peroxisome. (C) shows the morphology of peroxisomes in methanol-limited grown H. polymorpha. (D–F) Immunocytochemical localization of AO (D), CAT (E) and DHAS protein (F) in peroxisomes of cells grown in batch cultures on methanol. Note that DHAS is randomly present over the organelle whereas catalase is predominantly located at the edges of the organelle. For immunocytochemistry specific polyclonal antibodies against the three indicated proteins are used. M—mitochondrion; N—nucleus; P—peroxisome; V—vacuole. The bar represents 1 μm.