In
real-time PCR (qPCR), the same amplification procedure is used as in conventional
PCR. A segment of target DNA, which serves as a template, is combined in a single tube along with other components essential to the amplification reaction (e.g., thermostable DNA polymerases, forward and reverse primers, deoxynucleotide triphosphates (
dNTPs), and reaction buffer). The prepared tube is placed in an instrument, referred to as a thermal cycler. A thermal cycler is a laboratory apparatus that typically has a thermal block with holes where tubes holding the PCR reaction mixture are inserted. The reaction contents are then subjected to a series of time and temperature-dependent steps - denaturation, primer annealing, and extension. This series of steps is repeated 25 to 30 times, resulting in an exponential amplification of the DNA template.