TEMPERATURE STEP CORRECTION WITH DOUBLE SIGMOID LEVENBERG-MARQUARDT AND ROBUST LINEAR REGRESSION

摘要

Systems and methods for improving Ct determination in PCR amplification curvesby correctingPCR data for temperature shifts that may occur during the PCR process. Adouble sigmoid functionwith parameters determined by a Levenberg-Marquardt (LM) regression process isused to find anapproximation to the portion of the curve in the region after the temperatureshift, termed "CAC",the cycle where the temperature shift occurred. A robust linear approximationis determined for theportion of the curve in the region before the temperature shift. Values of thefluorescent intensityfor the cycle CAC or CAC+1 are determined using both the linear approximationand the LMprocess, and a difference in these values is subtracted off of the portion ofthe data set representingthe portion of the curve before the temperature shift occurred to produce ashift-corrected data set.The shift-corrected data set may be displayed or otherwise used for furtherprocessing.