Primer sets used to amplify and clone chitinase genes (chiA or chiB) into the pBAD TOPO TA expression vector. Additional nucleotides (underlined) were added to incorporate an additional stop-codon (TGA), ribosome binding site (AGGA) and start-codon (ATG). Mutagenic primers used to preform site-directed mutagenesis at the active site of the chitinase genes chiA or chiB. Flanking primers are equal to the primers used to produce the enzymatically active enzymes. Nucleotide substitution of the mutant primers is indicated in the box.