Spectrofluorometric detemination of ctDNA with CR

The characteristics of spectra,combined ctDNA with the different kings of fluorescent reagents,have been studied by the method of fluorescence spectroscopy.The experimental results showed that when ctDNA combined with CR,the fluorescence intensity was strengthened by little;whereas if CTMAB added to the combination,the fluorescence intensity was strengthened by large.Moreover,the relationship between the fluorescence intensity and the amount of ctDNA was linear within certain range.Based on this finding,a new fluorescence system for determination of the amount of ctDNA was established.When the temperature was 25℃,time range was 40mins,the concentration of CR was 8.0×10-6 mol·L-1,the concentration of CTMAB was 3.2×10-5 mol·L-1,and ctDNA concentration was 0.005~3.6 μg·mL-1,the linear relationship was significant.And the linear square was △F=131.22C+3.8543(C: μg·mL-1),the related coefficient was r =0.9988,and the detection limit was 0.01μg·mL-1.The proposed method had been successfully applied to the determination of DNA withdrawn from the alpaca blood,and the recoveries were in the range of 96.25% to 102.50% with satisfactory results.