TaqMan probes are short, single-stranded DNA molecules that are designed to anneal specifically to a target DNA sequence during a polymerase chain reaction (PCR).

They are called "TaqMan" probes because they were first developed for use with Taq polymerase, a heat-stable enzyme commonly used in PCR.

TaqMan probes are typically labeled with a fluorescent reporter dye at one end and a quencher molecule at the other end.

The reporter dye emits fluorescence when excited by a specific wavelength of light, but this fluorescence is quenched when the probe is intact due to its proximity to the quencher molecule.

During the PCR reaction, the TaqMan probe is cleaved by the Taq polymerase when it encounters the target DNA sequence. This separates the reporter dye from the quencher, allowing the dye to emit fluorescence.

The amount of fluorescence emitted is proportional to the amount of target DNA present in the sample, allowing for quantification of the target DNA.

TaqMan probes are often used for real-time PCR, also known as quantitative PCR (qPCR), because the fluorescence can be measured during the PCR reaction in real-time, providing quantitative data.

TaqMan probes are highly specific, as they are designed to anneal only to the target DNA sequence, reducing the risk of nonspecific amplification.

These probes are widely used in research, clinical diagnostics, and other applications where accurate quantification of DNA is important.

TaqMan probes have been instrumental in advancing fields such as genomics, molecular biology, and diagnostics, enabling researchers and clinicians to study and diagnose diseases with high precision.