Answer:
Fragments of DNA that have desired genes are isolated to form recombinant DNA for use in a host.
Explanation:
The first step in the genetics therapy it is to isolate the gene of interest. You can see this procedement in the image below.
The Cas9 of the image is the CRISPR associated with the protein 9. CRISPR is a bacteria's enzym which can edited portions of ADN.