Development and Testing of Trial Samples for Specific Serodiagnosis of Fasciola gigantica via External Quality Assessment

Objective: To build a procedure for production of samples for specific serodiagnosis of anti-Fasciola gigantica antibodies via an external quality assessment scheme, and to evaluate the homogeneity and stability of the trial samples. Methods: In this experimental study, samples contained an anti-Fasciola gigantica antibody according to screening by ELISA, followed by confirmation by Western blotting were collected. All samples were tested and found negative for other helminth, especially of trematode antibodies. The samples were also negative for anti-HIV-1 and -2 antibodies, anti-HCV antibodies, and HBs antigen. The samples were prepared by freeze-drying and freezing methods, the stability and homogeneity were evaluated each 2, 4, 8, 12 and up to 24 weeks. Results: We produced three lots of serum samples containing anti-Fasciola gigantica antibodies at three levels. Lot DK1 had optical density, OD=0.350 ± 0.037; Lots DK3 and DL3 had O=0.653 ± 0.046, and Lot DL1 had OD=0.850 ± 0.047 with the wavelength of 450 nm. The specific IgG antibodies against Fasciola gigantica antigens were found to be positive for all three proteins, 8–9 kDa protein (P 8-9), 28 kDa (P 28), and 42 kDa (P 42) by the Western blot technique. The trial samples were confirmed to be homogeneous by Fisher’s test (F statistics0.05) as well as to be stable during 24 weeks (with t statistics0.05). Conclusion: Trial samples for specific serodiagnosis of anti-Fasciola gigantica antibodies via external quality assessment can be produced with homogeneity and stability lasting for 24 weeks by freeze-drying and freezing methods.