TaqMan™ probes are hydrolysis-probes suitable for quantification analysis with qPCR.
Hydrolysis-probes are single stranded DNA oligos labeled with a fluorophore on one end and a quencher on the other end. The quencher surpresses the fluorescence unless the probe binds to an amplicon and the polymerase with its exonulease activity cuts off both labelings. Then a fluorescence will occur subsequently to a trigger beam and can be measured.
The amount of free fluorophores – and thus the fluorescence signal – is proportional to the amount of amplified DNA .