14 
Slide 1 
May I have the next slide (2)? 
I don't want to go into the technical details of the procedure; I 
would just like to outline it for those of you who would like to follow it. 
One can take two DNA molecules, cut them in such a way as to convert them 
into linear structures, and then by the use of appropriate enzymes modify 
the ends in such a way that it is possible to fuse short tails of polynu- 
cleotide sequences so that the tails of one of the linear molecules are 
capable of interacting with the tails of another molecule: in this par- 
ticular case, tails of polydeoxy A and these molecules with polydeoxy T. 
Since these ends are, in fact, cohesive with respect to each other, it 
is just possible to mix these two DNA molecules together and allow them to 
join to form this circular structure held together by these cohesive ends. 
Again, with the appropriate use of enzymes, which are available to us in 
highly purified form, it is possible to chemically join the ends of these 
structures, producing a chemically sealed structure that now contains the 
DNA elements provided by one donor and the DNA elements provided by a 
second donor. 
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