076

I '    1

Phage X DNA

DNA to be cloned

EcoRI

\

EcoRI

i

Left "arm” --15 kb —*• Right “arm”

Not necessary for X replication

5'

5'

3' i    - • mmm 5'

Restrictlon fragments of different sizes

5'

EcoRI

15 kb

Arms contain all the genes needed for replication but are too smali for packaging

Suitable size for 5' packaging after ligation with arms

Packaging of DNA in X particles using protelns and enzymes from k-infected £. coli

Infection of £. coli cells for X replication to clone the DNA