Molecular Beacons and Fluorescence Detection

Molecular Beacons

• In the presence of a specific product, the probe forms a stem-loop structure.

Fluorescence Detection

• Molecular Beacons are detectable when the specific product is present.

FRET Basics

• When the donor and acceptor probes are brought within 1 to 10 nm through specific DNA binding, energy transfer occurs from the donor to the acceptor.
• The role of the acceptor probe in FRET is to absorb energy from the donor probe and emit it at a different wavelength.

FRET Principles

• The amount of fluorescence is directly proportional to the amount of target molecules in the sample.

FRET Probe Cleavage

• The enzyme responsible for cutting the FRET probe in the overlapping region is a nuclease.

Cycling Probe Amplification

• The cycling probe method of amplification uses a synthetic probe consisting of DNA and RNA sequences arranged in a DNA-RNA-DNA sandwich sequence.

Quencher Dye Role

• The quencher dye in the cycling probe method of amplification is responsible for absorbing the energy from the reporter molecule when the probe is intact.

FRET Signal Production

• The amount of signal produced in the FRET probe method is directly related to the amount of target molecules in the sample.

Reporter Molecule Role

• The purpose of the reporter molecule in the FRET probe method is to emit fluorescence when the probe is cleaved, indicating the presence of the target molecule.

Test your knowledge on Molecular Beacons and their fluorescence detection in this quiz. Learn about the factors affecting the amount of fluorescence and the relationship with the template. Find out if the fluorescence is directly or inversely proportional to the template amount.