Plaque assays were done to isolate those white recombinant clones for rhBMP2 and 3. PCR analyses of viral DNAs were done to identify the target DNAs in recombinant viruses .

• 空斑形成后，经X-gal染色，挑取白色的单个重组克隆保存，取B2和B3各5个白色克隆进行第一轮扩增，收集病毒上清。