title: [Optimization of productivity of Epstein-Barr virus membrane antigen in baculovirus infected insect cells].
abstract: OBJECTIVE
  To probe factors influencing the expression level of in insect cells.
  
  
  METHODS
  Insect cells at different growth phases and in different culture media were infected with recombinant baculovirus carrying EBV-MA gene, where the membrane anchor sequence was deleted. The expression level of EBV-MA was detected by immunodots assay and scanner analysis.
  
  
  RESULTS
  Cells at the early exponential phase yielded more expressed recombinant EBV-MA than those at the late exponential and stationary phases. Infected cells supplemented with fresh medium at various phases of growth resulted in improved productivity of EBV-MA. Further experiments revealed that replacing fresh medium prior to infection and supplementing a mixture of glucose and glutamine after infection, the productivity could be improved dramatically. Comparing the productivity of EBV-MA expressed in sf9 cells with that in sf21 cells, no obvious difference was found.
  
  
  CONCLUSIONS
  Consumption of nutrients and accumulation of metabolites in cell culture media were the important factors influencing the productivity of EBV-MA in insect cells.
authors.affiliation: Institute of Virology, Chinese Academy of Preventive Medicine, Beijing 100052.
authors.forename: J
authors.initials: J
authors.lastname: Lu
authors.forename: W
authors.initials: W
authors.lastname: Zhou
authors.forename: S
authors.initials: S
authors.lastname: Gu
mesh_terms: D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D046508:Culture Techniques / Q000379:methods; D014162:Transfection; D014763:Viral Matrix Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C037662:EBV-associated membrane antigen, Epstein-Barr virus; D014763:Viral Matrix Proteins