Ya, I have to quantify the increased or decreased expression.
Ok, does Calibrator mean a reference gene?
its the gene of interest from the control/ wild type sample?
You can call a Calibrator as a reference gene but REMEMBER its different form Housekeeping genes.
Qiagen has defined Calibrator samples as: This is a reference sample used in relative quantification (e.g., RNA purified from a cell line or tissue) to which all other samples are compared to determine the relative expression level of a gene. The calibrator sample can be any sample, but is usually a control (e.g., an untreated sample or a sample from time zero of the experiment.
Basically, it can be a control from your experiment. When using the double delta Ct method for data analysis you need the calibration value for analysis. This would be an important control for measuring inter- assay variability that may occur when multiple samples are run on different plates.