1. Seed ~4.5 x 106 cells onto a 10 cm dish a day before transfection. Use low passage cells (not more than P15). Do not allow cells to grow to confluence.
2. Remove media and replace with IMDM media for at least 2 hrs.
3. Mix plasmids with 0.1x TE to a final volume of 450 ul in 15ml tubes.
4. Add 50 ul of 2.5 M CaCl2 to the plasmid mix.
5. Allow to mix at RT for 5 minutes.
6. Apply 500 ul of 2x HBS dropwise to the plasmid mix while vortexing at full speed.
7. Apply the precipitate to the 293T cells, dropwise around the entire dish.
8. Incubate 293T cells O/N (14-16 hrs).
9. Replace media with fresh DMEM complete media.
IMDM media
IMDM (Iscove) 44.75 ml
FBS 5
Pen/Strep 0.25
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Total 50 ml
2x HBS (store at -20 or -80 oC)
281 mM NaCl
100 mM HEPES
1.5 mM Na2HPO4, pH 7.12
Filter sterilize (0.22 um)
CaCl2 (store at -20 oC)
2.5 M CaCl2
Filter sterilize (0.22 um)
0.1x TE buffer (store at 4 oC)
10 mM Tris (pH 8.0)
1 mM EDTA (pH 8.0)
Dilute 1:10 with ddH2O
Filter sterilize (0.22 um)