Virus production from packaging cell* containing N2 
Neo virus* 
cell hne 
M2 virus* 
infected 
cell ciooe 
Neo virus 
titer 
(CFU/mJ) 
Helper 
titer 
(FFU /ml) 
Neo vinis 
titer after 
helper virus 
infection 
(CFLWml) 
PA12 
1 
3 x 10* 
20 
2 
4 x 10* 
<1 
3 
2 x 10’ 
40 
4 
1 x 10’ 
190 
5 
5 x 10* 
200 
PA317 
1 
t x 10* 
<1 
2 x 10’ 
2 
1 x 10* 
<1 
3 
2 x 10* 
<1 
3 X 10’ 
4 
4x 10* 
<1 
5 
2x 10* 
<1 
« 
1 x 10 5 
<1 
4x10’ 
7 
4 x 10* 
<1 
1 x 10’ 
• 
6 x 10* 
<1 
10 
2 x 10* 
<1 
11 
1 x 10’ 
<1 
Population' 
(x 10* 
<1 
* For experimental condition*, see Table 2. footnote m. 
* FFU, Focus-forming units. 
* A population of over 100 independent done* was analyzed to check for 
lire event* leading to helper virus production. 
Table 3. (Miller and Buttimore, 1986) 
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Recombinant DNA Research, Volume 12 
