This document outlines the 7 steps to design a TALEN sequence to knockout a gene: 1) Design the TALEN sequence, 2) Amplify the sequence via PCR, 3) Assemble the TALEN gene and insert it into an expression vector, 4) Transfect the vector into desired cells, 5) The TALEN pair binds DNA and causes cleavage, 6) A double strand break occurs and non-homologous binding leads to, 7) Mutation of the DNA and knockout of the target gene, resulting in knockout mice.