由於細胞培養可於體外呈現生物組織或個體之生理反應，因而逐漸取代動物實驗。而近幾年細胞療法的興起，使得細胞體外培養成為重要的議題；然而，細胞療法最大的瓶頸是無法在體外快速的培養至臨床所需細胞數量。目前大多以胎牛血清(fetal bovine serum, FBS)做為培養基補充劑，但胎牛血清的生產與應用存在科學及倫理爭議。在科學上，血清的組成複雜易變動，且伴隨高污染風險，因此常對科學研究的品質造成影響；在倫理上，剝奪胎牛生命與不人道的採集方式常被詬病。有鑑於此，科學家藉由開發合成化學培養基、合成血清替代物或初乳等進行無血清細胞培養。近年來包括人類臍帶血血漿、血小板濃厚血漿與血小板溶解物亦應用於取代胎牛血清，並可應用於幹細胞醫療、組織工程或抗體之生產。未來目標期望自其他動物副產物生產胎牛血清替代物，在提升產業收益的同時，亦能兼顧動物福祉，減少倫理爭議。
In vitro cell culture is a reliable methodology to examine the actual physiological conditions of a specific tissue and organ and is a potential alternative to animal experiments for biomedical research. Ex vivo expansion of stem cells has become an important issue in cell therapy. However, the major concern of cell-therapy or tissue engineering approach is the restrained ex vivo expansion ability of cultured cells. Conventionally, ex vivo expansion of stem cell uses fetal bovine serum (FBS) as a nutrient supplement in the culture medium. However, the amount of FBS used in the cell culture medium must be minimized due to scientific and ethical dilemmas. Different FBS batches display quantitative and qualitative variations in their compositions, possibly causing the scientific problems. In the ethical respect, fetuses are exposed to pain and discomfort and therefore the current practice of fetal blood collection is inhumane. Due to the drawbacks of FBS, the demand for a serum-free medium (SFM) has increased. Chemically defined media, synthetic serum replacement or bovine colostrums have been successfully applied to serum free cell cultivation for this purpose. In recent years, the application of homologous cord blood plasma, platelet-rich plasma and platelet lysate on cell cultivation have been attempted. The use of blood products derived from mature livestock as a serum replacement may mitigate the ethical and scientific controversies of FBS.
