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Updated: Aug 16, 2026

Detection of Low Copy Number Integrated Viral DNA Formed by In Vitro Hepatitis B Infection
Published on: November 7, 2018
[Genotyping of hepatitis E virus by PCR combining with single restriction endonuclease analysis]
Ning Pan1, Xing Dai, Ji-hong Meng
1Department of Microbiology and Immunology, Southeast University School of Medicine, Nanjing 210009, China.
Objective:
To develop a simple method for genotyping of hepatitis E virus (HEV) and to investigate HEV genotype distribution in Nanjing area.
Methods:
Twenty-seven full HEV sequences currently-available in GenBank were analyzed with MegAlign and MapDraw programs of DNA STAR software. Degenerate primers were designed and applied to amplify a fragment in HEV ORF1 region. HEV genotypes were determined by the size of the PCR products and by single restriction endonuclease analysis.
Results:
The PCR products of HEV genotype 1 and 2 were 275 bp and 269 bp in size. Distinctively, the PCR products of genotype 3 and 4 were 317 bp and 314 bp in size. Moreover, the PCR products of genotype 1 could be digested by Nae 1, but the products of genotype 2 could not. Distinctively, the PCR products of HEV genotype 3 could be digested by Not 1, but the products of genotype 4 could not. Six HEV reference strains standing for different HEV genotypes were clustered into their own types as predicted. Within 43 HEV IgM-positive clinical specimens collected in Nanjing, 19 were HEV PCR-positive and identified as genotype 4.
Conclusion:
A simple method of PCR combined with single restriction endonuclease analysis is developed for HEV genotyping. This assay allows rapid identification of a large number of HEV isolates directly from clinical specimens. Among patients with hepatitis E in Nanjing, most were infected with HEV genotype 4.

