Amplify 500–1000 bp DNA segment of 5′ upstream and 3′ downstream regions to the spacer sequence of the identified TALEN binding site using a PrimeSTAR GXL PCR Kit. Use primers including NheI or MluI sites at their 5′ ends to amplify the upstream DNA segment. Similarly, use primers including recognition sites for ApaI, XhoI, ClaI, EcoRV, or EcoRI at their 5′ end to amplify the downstream DNA segment. Insert the upstream DNA segment into the NheI and MluI sites of pZwitch as the left homology arm, and the downstream DNA segment into ApaI, XhoI, ClaI, EcoRV, and EcoRI sites as the right homology arm via restriction enzyme cloning. Purify the DNA of the resulting pZwitch construct and perform DNA sequencing of the cloned homology arms using the following primers: