TaqMan real-time PCR quantification: conventional and modified methods.

TaqMan real-time polymerase chain reaction (PCR) is a sensitive and reliable method that is widely used around the world. However, its inability to carry out assays using only small amounts of template DNA represents a serious limitation of the method. Recently, measurement of very small quantities of DNA became possible when a slight modification was applied to the conventional TaqMan real-time PCR method. Using the modified real-time PCR method, we were able to measure very small amounts of DNA template, and succeeded in comparing the levels of aldosterone synthase gene expression in samples of cardiac tissue from patients diagnosed with heart failure and control subjects.