Nucleic acid amplification method, a reagent and a reagent kit for use therein

An object of the present invention, in detection systems of nucleic acids using an internal standard, while ensuring an accurate measurement of the target nucleic acid, to provide a method and a reagent kit for use therein capable of amplification of stable internal standard were is there. The present invention provides a method for amplifying a target nucleic acid in a sample using an internal standard, the effect of an internal standard to the amplification reaction of a target nucleic acid by amplification product of the internal standard by amplifying ahead of the target nucleic acid nucleic acid amplification method, wherein the preventing, a reagent and reagent kit used therefor.