Sortases catalyze a transpeptidation reaction, where the enzyme cleaves the amide bond between the threonine and glycine of the sortase recognition sequence (LPXTG for S. aureus Sortase A), generating a thioacyl intermediate. Subsequently, this intermediate is resolved by the N-terminus of an oligoglycine nucleophile, creating a new peptide bond that links the substrate to the incoming nucleophile. Sortase variants are available that may exhibit enhanced activity with the substrate of interest. This kit provides wildtype Sortase and four different mutants to evaluate which sortase is best for the chosen application.