Disclosed is an adapted Madin-Darby canine kidney cell line capable of suspension culture in the absence of serum, and a chemically-defined medium for culture of the adapted MDCK cell line. Further disclosed are culture methods for growing the adapted MDCK cell line and methods for producing a vaccine from the adapted MDCK cell line grown in the chemically-defined medium.本發明揭示能夠在血清不存在下懸浮培養之適應馬丁達比犬腎(Madin-Darby canine kidney)細胞株及用於培養該適應MDCK細胞株之化學性界定培養基。本發明進一步揭示使該適應MDCK細胞株生長之培養方法及從生長在該化學性界定培養基中之該適應MDCK細胞株製備疫苗之方法。