As shown in Figures 3-4 and Table II, using the LNL6 vector 
supernatant to transfect CML cells (10 particles:! cell), we 
achieved transduction frequencies in the range of 10% as indicated 
by colony growth in methylcellulose containing the antibiotic G418 
at 1.2 mg/ml. If we expose 1.2 x lo’ marrow or 4.2 x lo’ peripheral 
blood cells to the marking vector (30% of an engrafting dose of 
marrow cells), we would expect to label 1.2 x 10® (10% efficiency) 
bone marrow cells and 4.2 x 10® peripheral blood cells (see Table 
I) . If we then consider that the patients may be in chronic phase 
or cytogenetic remission, such that the highest ratio of blast 
cells to normal cells is 1 in 100 or 1%, then we would expect to 
label 1.2 x 10® marrow blasts and 4.2 x 10® peripheral blood blasts 
maximum (see Table I) . The ratio of marked blasts to unmarked 
cells is 1:3000 at the time of freezing (see Table III). 
Table III 
The Ratio of Leukemia to Normal 
Transformation 
Frequency 
Marrow 
Peripheral blood 
Leukemia/ Normal = 
1.2 X 10® marked blasts 
4.2 X 10® marked blasts 
3.78 X lo’ unmarked cells 
1.26 X 10^° unmarked cells 
Leukemia/Normal = 
3 X 10'^ 
3 X 10'^ 
Leukemia/ Normal = 
0.0003 or 
1 marked leukemia cell 
0.0003 or 
1 marked leukemia cell 
3333 unmarked cells 
3333 unmarked cells 
Recombinant DNA Research, Volume 14 
[753] 
