Patent ID: 6387621
Filing Date: 2002-05-14
Classification: C12Q,G01N

Abstract:
A method for determining the presence of a nucleic acid comprising the steps ofproviding a fluorescent entity capable of indicating the presence of the nucleic acid and capable of providing a signal related to the quantity of the nucleic acid, amplifying the nucleic acid through a plurality of amplification cycles in the presence of the fluorescent entity, measuring fluorescence intensity of the fluorescent entity at each of the plurality of amplification cycles to produce a fluorescent value for each cycle related to the quantity of the nucleic acid present at each cycle, generating a fluorescence-verses-amplification-cycle plot wherein the fluorescent values are recorded for each amplification cycle, calculating slopes of segments of the fluorescence-verses-amplification-cycle plot using a plurality of the fluorescent values, using the segment slopes of the fluorescence-verses-amplification-cycle plot to establish a baseline fluorescence region by generating a slope value for each of a plurality of the amplification cycles, and establishing the baseline fluorescence region comprising an interval of cycles that includes the amplification cycle with the slope value having an absolute value closest to zero, and ascertaining whether the fluorescence value during a selected amplification cycle is outside the baseline fluorescence region.