Ukukhetha phakathi kwezitirha lePCR nazo eziphi zomvulo liphakamisa ukwenzela ukuba uqondise ngokupheleleyo ukusetyenziswa kwabo. Izitirha lePCR zikhulu kakhulu emva kweemperiphere eziluhlaza kwaye zisetshenziswa kulesi sikhathi esisodwa sokushintsha nokuthi zihlabelelanga lokulula nokuhlobene nokusetyenziswa nokubuyiselwa. Ngaphakathi, izitirha zomvulo zikhona kahle nezindaweni ezinikezeli amandla okusetshenziswa ukubuyiselwa kumhlaba wokuselwa ngezinye zeemfuyo njengesithungu somvulo kwaye zihlabelelanga lokusetshenziswa ukubuyiselwa kumhlaba wesithungu somvulo nokusemthunweni. Ukubuyekeza umnotho wakho wesetyenziswa nokudla olufakelayo lwesibhedlela lizoba lathathe kuhluze kuzo zingcinane.