Compounds of the invention are amine oxide prodrugs showing activity on the NK1 receptor. Thus, it is possible to suppress a surge voltage which is generated when the IGBT is turned OFF during the flow of an over-current. The method involves contacting nucleic acid fragments in a sample in amplifying conditions with a nucleic acid polymerase; regular primer oligonucleotides having sequences comprising hybridizable portions of known terminal subsequences; and a poisoning oligonucleotide primer.