AIM: To investigate the modification of baculovirus vectorand the feasibility of delivering exogenous genes intomammalian cells with the culture supernatant of Spodopterafrugiperta (Sf9) cells infected by recombinant baculoviruses.METHODS: Two recombinant baculoviruses (BacV-CMV-EGFPA,BacV-CMV-EGFPB) containing CMV-EGFP expressioncassette were constructed.HepG2 cells were directlyincubated with the culture supernatant of Sf9 cells infectedby recombinant baculoviruses,and reporter gene transferand expression efficiencies were analyzed by flow cytometry(FCM).The optimal transduction conditions were investigatedby FCM assay in HepG2 cells.Gene-transfer and expressionefficiencies in HepG2 or CVl cells by baculovirus vectorswere compared with lipofectAMINE,recombinant retrovirusand vaccinia virus expression systems.Twenty differentmammalian cell lines were used to investigate the feasibilityof delivering exogenous genes into different mammalian cellswith the culture supernatant of infected Sf9 cells.RESULTS: CMV promoter could directly express reportergenes in Sf9 cells with a relatively low efficiency.Targetcells incubated with the 1:1 diluted culture supernatant(moi=50) for 12 h at 37℃ could achieve the highesttransduction and expression efficiencies with leastimpairment to cell viability.Under similar conditions thebaculovirus vector could achieve the highest gene-transferand expression efficiency than lipofectAMINE,recombinantretrovirus and vaccinia virus expression systems.Mostmammalian cell lines could be transduced with recombinantbaculovirus.In primate adherent culture cells therecombinant baculovirus could arrive the highest infectionand expression efficiencies,but it was not very satisfactoryin the cell lines from mice and suspended culture cells.CONCLUSION: Mammalian cells incubated with the culturesupernatant of infected Sf9 cells could serve as a veryconvenient way for rapid and efficient expression of foreigngenes in mammalian cells,but it might be more suitable forprimate adherent culture cells. AIM: To investigate the modification of baculovirus vectorand the feasibility of delivering exogenous genes into mammalian cells with the culture supernatant of Spodoptera frugiperda (Sf9) cells infected by recombinant baculoviruses. METHODS: Two recombinant baculoviruses (BacV-CMV-EGFPA, BacV- containing CMV-EGFP expressioncassette were constructed. The optimal transduction conditions were investigated by FCM assay in HepG2 cells. Gene-transfer and expressionfficiencies in HepG2 or CV1 cells by baculovirus vectorswere compared with lipofectAMINE, recombinant retrovirusand vaccinia virus expression systems. Twenty differentmammalian cell lines were used to investigate the feasibilityof deliveringexogenous genes into different mammalian cellswith the culture supernatant of infected Sf9 cells. RESULTS: CMV promoter could directly express reportergenes in Sf9 cells with a relatively low efficiency. Target cells incubated with 1: 1 diluted culture supernatant (moi = 50) for 12 h at 37 ° C could achieve the highest transmission and expression efficiencies with leastimpairment to cell viability. Unide similar conditions thebaculovirus vector could achieve the highest gene-transferand expression efficiency than lipofectAMINE, recombinant retrovirus and vaccinia virus expression systems. Hostmammalian cell lines could be transduced with recombinant baculovirus. primate adherent culture cells therecombinant baculovirus could arrive the highest infectionand expression efficiencies, but it was not very satisfactory in the cell lines from mice and suspended culture cells. CONCLUSION: Mammalian cells incubated with the cultures of supernatant of infected Sf9 cells could serve as a veryconvenient way for rapid and efficient expression of foreigngenes in mammalian cells, but it might be more s uitable forprimate adherent culture cells.