From co-culture to defined medium: State of the art and practical considerations

Embryo culture in domestic and laboratory animals, and also in humans has d eveloped significantly during recent decades. It is the aim of this review to consider the historical development of different culture systems, with a special emphasis on the recent tendency to remove somatic cells and undefi ned proteins from the culture systems for sanitary reasons. In addition to the sanitary aspect, developing more standardized culture conditions is use ful for diminishing variation between laboratories and for studying the nee ds of the embryo.