Patent ID: 6613509
Filing Date: 2003-09-02
Classification: C12Q,Y10S

Abstract:
A method for determining the nucleotide composition of an oligonucleotide which comprises the steps of:(a) incorporating a stable, isotope-labeled form of one of the four nucleotide units of an oligonucleotide into the oligonucleotide under investigation in place of the ordinary nucleotide therin, the other three types of nucleotides in the oligonucleotide being unlabeled; (b) measuring the mass peak of the unlabeled oligonucleotide using mass spectrometry; (c) measuring the mass peak of the labeled oligonucleotide using mass spectrometry; (d) obtaining the magnitude of the mass shift between the labeled oligonucleotide and the unlabeled oligonucleotide, whereby the number of isotope-labeled nucleotides in the oligonucleotide under investigation is determined; and (e) comparing the number of isotope-labeled nucleotides with the number of that type of nucleotide in a reference oligonucleotide.