The new GeneMorph® II EZClone Domain Mutagenesis Kit* offers an easy and fast cloning method (Figure 1) to perform targeted random mutagenesis on protein domains and promoter elements, while delivering uniform mutational spectrum. The kit contains Mutazyme® II DNA polymerase, which introduces a more uniform mutational spectrum compared to other error-prone PCR enzymes so that mutations at As and Ts occur at the same frequency as Gs and Cs (Figure 2). This allows you to generate all types of random mutations without a bias to more rapidly discover key sites responsible in structure-function rela- tionships. This enhanced version makes cloning and library construction easier than ever.