Detection of Loop-meditated Isothermal Amplification Products by Capillary Electrophoresis

KeyWord:loop-mediated isothermal amplification  capillary electrophoresis  false-positive product

Abstract:

      A novel method was proposed for the detection of loop mediated isothermal amplification(LAMP) products of Escherichia coli(E-coli)based on self-built capillary electrophoresis(CE)with lamp induced fluorescence system.Four primers were designed for the target DNA,and the sizes of the LAMP products of E-coli corresponding to the primers of F3,B3,FIP and BIP were 240 bp.The best result was achieved with the sieving polymer of 0.5% HEC(1 300 K),an electric field strength of 100 V/cm and an injection time of 1.0 s at the electric field strength of 100 V/cm.The migration time of DNA from 100 bp to 500 bp is linearly related with DNA size,and the correlation coefficient is 0.996.The LAMP products of E-coli were resolved under the same electrophoretic conditions.The sizes of the LAMP products were calculated based on the linear relationship,and the positive products was distinguished from the false-positive products.The results demonstrated that CE could not only rapidly separate the LAMP products of E-coli within 15 min,but also distinguish the positive from false-positive products.The proposed method was successfully applied in the separation of the LAMP products of AB0174 E-coli.Therefore,it is suitable for the rapid detection of LAMP products of DNA.