ObjectiveTo establish an identification method basis on molecular biology techniques for Clonorchis sinensis and Haplorchis taichui. MethodsAdult flukes of C. sinensis and H. taichui were collected from Clonorchiasis endemic areas and the eggs were separated from the worms under stereomicroscope. Roundworm, Whipworm, Hookworm and Pinworm were served as control species, all kinds of eggs were divided into five experimental groups according to the species and the number of eggs. DNA from each group was extracted and amplified the sequence of ITS-2, and amplified products were sequenced and homology analyzed ensure that the products were the target fragments. The species of insect were determined according to the electrophoresis of PCR products. ResultsThe electrophoresis of PCR products of C.sinensis and H. taichui display a distinct band at around 400bp, 500bp, respectively; electropherogram in PCR products of mixture DNA of two species eggs showed two obvious bands at around 400bp and 500bp. The two nucleotide sequencing which had sequenced were compared to Blast, show that both of the sequences are highly homologous with C.sinensis and H.taichi in GenBank , respectively. The PCR products with four kinds of Heligmosomoides polygyrus eggs have no other bands except the objective strips. ConclusionThis method can be used to identify C. sinensis and H. taichui, and the results are not affected by four kinds of Heligmosomoides polygyrus eggs , is an identification method for Clonorchis sinensis and Haplorchis taichui with high sensitivity and specificity.

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