increase the efficiency of transduction. Two different 
marking vectors will be used to mark the bone marrow and 
peripheral blood target cells respectively. These two 
vectors will be distinguishable by PCR analysis, and will 
allow identification of cells originating from the marrow 
versus the peripheral blood graft post-transplant. The 
transduced marrow and peripheral blood populations will be 
given back to the patients along with non-transduced marrow 
and peripheral blood. The kinetics and biology of autologous 
reconstitution can be studied if successful marking of 
progenitors or stem cells is obtained, and if patients 
relapse post-transplant, the presence of marked tumor cells 
will indicate that the origin of the relapse is at least in 
part from the autografted marrow or peripheral blood. This 
type of information could help guide future approaches to 
autotransplantation, especially as regards the need for 
purging autografts of residual tumor cells. 
Recombinant DNA Research, Volume 16 
[147] 
