US Patent 7790368 Method for analyzing nucleic acid

A method is provided for analyzing nucleic acid comprising the steps of extracting, amplifying and detecting the nucleic acid of interest, wherein one or more internal control nucleic acids which can be detected and discriminated from the nucleic acid of interest are added for each step to a sample prior to the performance of each step, and the success or failure of each step is judged from the detection results obtained for the respective internal control nucleic acids in the detection step. The internal control nucleic acids added prior to each step can be discriminated from each other.