Monocyte/macrophage cell lines are fastidious cells commonly used in transi
ent transfection experiments. In the course (of a study of gene regulation
by lipopolysaccharide (LPS), lye have compared several methods for DNA-medi
ated cell transfection to determine which would be optimally applicable to
the macrophage line, RAW 264.7. Both the response level (LPS inducibility)
and the degree of inter-assay variation were evaluated for each transfectio
n technique The following methods were compared: LIPOFECTIN(R), LIPOFECTAMI
NE(TM), LIPOFECTAMINE PLUS(TM), SyperFect(TM), Ca-3(PO4)(2) DNA co-precipit
ation, DEAE dextran-mediated transfection and electroporation. The transfec
ted plasmid DNA included a luciferase reporter construct containing the jun
B minimal promoter under the control of an LPS-inducible 1300-bp regulatory
fragment downstream of junB 5'-flanking sequence, as well as a beta-galact
osidase reporter construct under the adenovirus promoter and enhancer used
as an internal control. Electroporation, followed by a resting period of 16
-24 h before stimulation with LPS, had the highest inducibility of all meth
ods. DEAE dextran and Ca-3(PO4)(2) precipitation showed the least and the g
reatest inter-assay variation, respectively. For all other methods, inter-a
ssay variability fell within this range. The results presented may serve as
both a general reference and a guide for reporter gene studies in this or
other macrophage cell lines.