Abstract:

A highly sensitive and selective detection method for DNA of cauliflower mosaic virus (CaMV) 35S promoter
(target DNA) was developed using a non-labeled molecular beacon (MB) and a nucleic acid dye TOTO-3. Under the
optimum conditions, the fluorescence intensity of TOTO-3 exhibited good linear dependence on the quantity of the target
DNA in the range of 2×10-10–200×10-10 mol/L. The fitted regression equation was Δ I = 2.022 2 C + 18.411 1, and the limit
of detection was 1 ×10-10 mol/L (3σ). The proposed method had a good precision, low detection limit, good selection and
high sensitivity. The detection of genetically modified food could be achieved by this proposed method based on asymmetric
polymerase chain reaction (PCR).

Key words: non-labeled molecular beacons, TOTO-3, fluorescence, genetically modified food, detection