Transfection of SF9 cells with Recombinant Bacmid DNA by xiaoyounan


									         Transfection of SF9 cells with Recombinant Bacmid DNA
             (from Gibco-BRL Bac-to-Bac Instruction manual)

1.    Seed 9 x 105 cells per well in 6-well plate in 2ml Grace’s media supplemented with
          10% FBS and antibiotic-antimycotic. Use only cells from 24h-old suspension
          culture in mid-log phase with a viability of >97%. Rock the plates (do not swirl)
          back-forth and from side to side to distribute the cells evenly.
2.    Allow cells to attach at 27C for at least 1 h.
3.    Prepare the following solution in eppendorf or 12 x 75-mm sterile polypropylene
              Solution A: For each transfection, dilute ~10l of “Quick and Dirty” prep of
              Bacmid DNA into 100l SF-900 SFM without antibiotics.
              Solution B: For each transfection, dilute 10-15l CellFECTIN Reagent into
              100l SF-900 SFM without antibiotics. Note: CellFECTIN Reagent is a lipid
              suspension that may settle with time. Mix thoroughly by inverting the tube 5-
              10 times before removing a sample for transfection to ensure that a
              homogeneous sample is taken.
4.    Combine the two solutions, mix gently, and incubate for 15-45 min at room
5.    Wash the cells once with 2 ml of SF-900 SFM without antibiotics.
6.    For each transfection, add 0.8 ml of SF-900 SFM to each tube containing the lipid-
          DNA complexes. Mix gently. Aspirate wash media from cells and overlay the
          diluted lipid-DNA complexes onto the cells.
7.    Incubate cells for 5 h in a 27C incubator.
8.    Remove the transfection mixtures and add 2-2.5ml of Grace’s media containing FBS
          and antibiotic. Put the plate in closed box with wet kimwipe on the bottom to
          prevent media evaporation. Incubate cells in a 27C incubator for 4-5 days.
9.    Harvest virus from cell culture medium, call it P0. Use1 ml for further amplification
          of virus in 100ml SF9 cells. Use the cells to run the SDS-page to verify
          expression of the recombinant protein.
10.    From the initial transfection, viral titers of 2 x 107 to 4 x 107 pfu/ml can be expected.
          For amplifying viral stocks, infect a cell culture at Multiplicity of Infection (MOI)
          of 0.01 to 0.1. Harvest virus at 72-96 h post-infection. That will result in
          approximately 100-fold amplification of the virus.
11.    Store virus at 4C, protected from light. For long-term storage of virus, the addition
          of FBS to a final concentration of at least 2% is recommended. Storage of an
          aliquot of the viral stock at -70C is also recommended.

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