The fluid in which cells or tissues, including eggs, sperm and embryos, are grown. It consists of water, salts and nutrients. Different media have turned out best for different purposes. In the early days of in vitro fertilisation, several different media seemed to produce equal results: examples included Ham's F10, Whittingham's T6. Quinn's medium (said to be based on human tubal fluid, though in reality different to the fluid in the fallopian tube) produced better results than the first generation media. Today's third generation media, or stage specific media, give superior results and are used increasingly. Plural: culture media.

Embryo culture medium formulated to resemble the constituents found within the fallopian tube by Dr Patrick Quinn, an Australian scientist living in Los Angeles, but differing in a number of respects.