Electron Microscopy: Ribosomes

In secretory cells, the cytoplasm is full of ribosomes translating mRNA coding for secretory proteins. Each dot seen on the micrograph represents a ribosome.

Photo: Electron micrograph of salivary glands in Chironomus tentans. Hans Mehlin, Department Cell and Molecular Biology, Karolinska Institutet and Nobelprize.org.