An improved method for recovering the protein expressed by open reading frame 2 from porcine circovirus type 2 is provided. The method generally involves the steps of transfecting recombinant virus containing open reading frame 2 coding sequences into cells contained in growth media, causing the virus to express open reading frame 2, and recovering the expressed protein in the supemate. This recovery should take place beginning approximately 5 days after infection of the cells in order to permit sufficient quantities of recombinant protein to be expressed and secreted from the cell into the growth media. Such methods avoid costly and time consuming extraction procedures required to separate and recover the recombinant protein from within the cells.本發明提供一種用於自第二型豬環狀病毒中回收藉由開放閱讀框架2表現之蛋白質的改良方法。該方法一般涉及以下步驟:將含有開放閱讀框架2編碼序列之重組病毒轉染至包含於生長培養基中之細胞中,引起該病毒表現開放閱讀框架2,及回收在上清液中之經表現之蛋白質。應在細胞感染大約5天之後開始進行此回收以容許足量重組蛋白質表現且自細胞分泌至生長培養基中。該等方法避免需要自細胞內分離及回收重組蛋白質之昂貴及費時的提取程序。