Cultivation of viruses

This chapter discusses the process and results of cultivation of viruses. Viruses can only replicate in living cells. For studies of the growth of viruses and for the production of virus components, it is, therefore, necessary to have access to cells cultivated in the laboratory. Cell cultures are also of dominating importance for the isolation of infectious agents in the diagnosis of virus infections. Cell cultures are established by the propagation of dispersed cells. In some cases, such cells may grow in suspension, but most often, they grow as a monolayer on the supporting material. Cultures established by cultivation of the cells that have been released from organ fragments are called primary cell cultures. The cells from a primary culture can be increased in number by passaging, which means that the cells are transferred from one cultivation vessel to another, where they are again allowed to form a monolayer.