Design of targeting construct is important to allow screening for targeting construct insertion at the homologous site

In both cases, it is important to have probes that are specific for sequences outside of the targeting vector. This is so that it will detect sequences at the correct endogenous site rather than wherever the targeting construct may integrate.

The first example deletes a restriction site

The second example inserts a restriction site

ut is for untargeted clone, T is a targeted clone

by S. Pearson-White