* This is a commonly used antibody mutagenesis technique that can randomly introduce mutations throughout the entire antibody gene or within specific regions. During polymerase amplification of the target gene, mutations are randomly introduced at a certain frequency by employing low-fidelity polymerases or adjusting reaction conditions. Multiple rounds of PCR are performed to iteratively introduce random mutations, accumulating the mutational effects, ultimately yielding random mutants of the target protein.

* Chain shuffling involves retaining either the heavy chain or light chain of a specific antibody, while pairing it with a randomized complementary chain. Higher-activity mutants are then selected through screening of the phage antiboyd library.

* Somatic hypermutation occurs predominantly in the CDR regions, which directly contact the antigen. During in vitro antibody affinity maturation, the CDR regions are frequently chosen for site-directed mutagenesis. When performing site-directed mutagenesis on CDRs, multiple CDRs can be mutated in parallel or optimized sequentially.

* DNA Shuffling Technology involves cleaving homologous antibody genes into fragments not exceeding 50 bp using DNase I. These fragments are then randomly reassembled and amplified by PCR into full-length antibody genes.