Molecular beacons are structured probes that are highly sensitive, sequence specific, and are used for sequence detection in qPCR and in vitro studies.
A Molecular beacon is a single-stranded bi-labeled fluorescent probe held in a hairpin-loop conformation (around 20 to 25 nt) by complementary stem sequences (around 4 to 6 nt) at both ends of the probe. The 5’ and 3’ ends of the probe contain a reporter and a quencher molecule, respectively. The loop is a single-stranded DNA sequence complementary to the target sequence. The proximity of the reporter and quencher causes the quenching of the natural fluorescence emission of the reporter. The structure and mechanism of a molecular beacon is shown below.
Figure 1.Molecular Beacons Work
Molecular beacons hybridize to their specific target sequence causing the hairpin-loop structure to open and separate the 5’ end reporter from the 3’ end quencher. As the quencher is no longer in proximity to the reporter, fluorescence emission takes place. The measured fluorescence signal is directly proportional to the amount of target DNA.
Our probes are provided in a format to simplify your experimental planning.
*Estimate is based on 3 nmol or 32 µg for 1 OD and 200 nM in 25 µL reaction (5.0 pmol/reaction). Estimate is based on an average sequence length of 30 bases.
The most common fluorophore and quencher combinations are listed below:
Spectral Properties Table
*Delivery times may be longer due to international transit, customs clearance delays, etc. Large projects will be placed on a delivery schedule based upon project needs.