Analysis of biomolecules is required in many biomedical research areas.
A spectrofluorimetric method is proposed for determination of calf thymus DNA
(ctDNA) based on the fluorescence enhancement of terbium-danofloxacin (Tb3+-Dano)
in the presence of ctDNA.
Methods: A probe with maximum
excitation and emission wavelengths of 347 nm and 545 nm, respectively, was
developed. The enhanced fluorescence intensity of Tb3+-Dano system
was proportional to the concentration of ctDNA. The effective factors and the
optimum conditions for the determination of ctDNA were studied. Under the
optimum conditions of [Tris buffer]= 0.01 mol L-1 (pH 7.8), [ Tb3+]=
1×10-5 mol L-1 and [Dano]= 5×10-5 mol L-1,
the maximum response was achieved. The developed method was evaluated in terms
of accuracy, precision and limit of detection.
Results: The linear concentration
range for quantification of ctDNA was 36-3289 ng mL-1 and the
detection limit (S/N=3) was 8 ng mL-1. The concentration of DNA
extracted from Escherichia coli as an extracted sample was also
determined using the developed probe. The concentration of DNA in extracted
sample was determined using UV assay and developed method, the results were
Conclusion: The proposed method is a
simple, practical and relatively interference free method to follow up the
concentrations of ctDNA.