This technique was further enhanced by the discovery that by avoiding the methyl-directed mismatch repair system, the frequency of obtaining recombinants can be increased to over 107/108 viable cells.
Denna teknik förbättrades ytterligare av upptäckten att man genom att undvika cellens metyleringsstyrda DNA-reparationssystem kan öka frekvensen rekombinanter till över 107/108 levande celler.