Figure 4.2-A. Evaluation of human epithelial (HeLa) cells for the expres- 
sion of adenoviral mRNA transcripts following infection with AvlCFl. The 
expression of adenovirus genes after infection of HeLa cells by the recom- 
binant adenovirus AvlCFl was examined for the expression of mRNA coding for 
the adenoviral hexon gene using northern analysis. HeLa cells were grown to 
80% confluency in Dulbecco's modified Eagle medium, 10% fetal calf serum, 
1% glutamine, 100 U/ml penicillin, 100 pg/ml streptomycin and infected at 
100 pfu per cell. After 4 days total RNA was extracted (Chirgwin et al., 
1979) and evaluated by northern hybridization analysis using as a probe a 
400 bp region of the hexon gene. Ad hexon mRNA was not detected in unin- 
fected 293 cells (lane 1) or in uninfected HeLa cells after short exposure 
(0.5 hr, lane 4) or long exposure (25 hr, lane 7). In contrast, Ad hexon 
mRNA was observed in 293 cells infected either by Ad-dl327 (lane 2) or 
AvlCFl (lane 3). HeLa cells infected by Ad-dl327 showed easily detectable 
levels of Ad hexon mRNA on short (lane 5) and long (lane 8) exposure. In 
contrast, HeLa cells infected by AvlCFl showed no Ad hexon mRNA on short 
exposure (lane 6) but, on long exposure (lane 9) small amounts were pres- 
ent. 
Recombinant DNA Research, Volume 16 
[697] 
