Background: Splicing by overlap extension (SOE) PCR is used to create mutation in the coding sequence of an enzyme in order to study the role of specific residues in protein’s structure and function. Objectives: We introduced a nested-SOE-PCR (N –SOE-PCR) in order to increase the specificity and generating mutations in a gene by SOE-PCR.   Materials and Methods: Genomic DNA from Bacillus thermo...