Overview: TaqMan real-time PCR is one of the two types of quantitative PCR methods. Unlike the other type of real-time PCR, the CYBR Green method, which uses a florescent dye that can bind to any double-stranded DNA, TaqMan uses a fluorogenic probe which is a single stranded oligonucleotide of 20-26 nucleotides and is designed to bind only the DNA sequence between the two PCR primers. Therefore only specific PCR product can generate fluorescent signal in TaqMan PCR. To do TaqMan PCR, besides reagents required for regular PCR, additional things required are a real-time PCR machine, two PCR primers with a preferred product size of 50-150 bp, a probe with a fluorescent reporter or fluorophore such as 6-carboxyfluorescein (FAM) and tetrachlorofluorescin (TET) and quencher such as tetramethylrhodamine (TAMRA) covalently attached to its 5' and 3' ends, respectively.