Jv. Omahoney et Te. Adams, OPTIMIZATION OF EXPERIMENTAL-VARIABLES INFLUENCING REPORTER GENE-EXPRESSION IN HEPATOMA-CELLS FOLLOWING CALCIUM-PHOSPHATE TRANSFECTION, DNA and cell biology, 13(12), 1994, pp. 1227-1232
We describe a highly efficient calcium phosphate transfection protocol
capable of achieving 100% transfection efficiency of reporter genes t
ransiently expressed in the human hepatoma cell lines HuH7 and HepG2,
This procedure, a modification of that described by Chen and Okayama,
is reliable, reproducible, and eliminates the requirement for the incl
usion of cotransfected internal control plasmids, While Chen and Okaya
ma described the pH of the 2x BBS (N,N-bis[2-hydroxyethyl]-2-aminoetha
nesulfonic acid-buffered saline) and DNA concentration as being critic
al factors for optimal transfection efficiency, we show that a reduced
and strictly monitored standing time of the DNA/CaCl2/2x BBS cocktail
prior to addition to cultured cells is essential for a particular com
bination of pH and DNA concentration. We also show that the inclusion
of internal control plasmids can inhibit reporter gene activity in a p
romoter- and dose-dependent manner. The method so described is also ap
plicable for the transfection of other mammalian cell lines including
COS and HeLa, and conceivably for the generation of stable transfectan
ts at high frequency.