Development of an Immunochromatographic Strip for Rapid Detection of Mink Enteritis Virus

Figures

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  Figure 1. Schematic diagram of the MEV competitive ICS assay. (A) Schematic side view of colloidal gold competition and the principle of detection. The sample contained the MEV, the colloidal gold-monoclonal antibody (MAb) 14 conjugates would combine with the MEV. When the antigen–antibody complex migrated to the C line, it would combine with goat anti-mouse IgG, and a band would appear at the C line (B). If two bands were observed at both the T and C lines, the sample was considered negative (C). The test is invalid if only one band appears at T line and no band is present (D).

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  Figure 2. Identification of MEV monoclonal antibody. (A) The immunofluorescence assay of MAbs against MEV in infected F81 cells (magnification, 100×). MEV-infected F81 cells were incubated with MAbs 4, 6, 8, 10, and 14 followed by FITC-conjugated secondary antibody. SP2/0 supernatant as a negative control. (B) The MEV VP2 protein was run for Western blotting using one of the MAbs 4, 6, 8, 10, and 14. SP2/0 supernatant and specific anti-MEV MAb F5 (Wang et al., 2009) served as negative and positive controls, respectively.

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  Figure 3. Characterization of the colloidal gold probes. Analysis of the 20-nm colloidal gold solution (A,B). (A) About 20-nm colloidal gold particles appear round or oval observed by transmission electron microscopy (TEM). TEM indicated that the diameters of the colloidal gold particles were approximately 20 nm. Bar = 100 nm. (B) Determination of homogeneity of 20-nm colloidal gold solution by UV-visible spectrophotometry. (C) Gold colloid-labeled MAb 14 appeared round or oval, and a white ring around the probe, without any sediment, as observed by TEM. Bar = 100 nm.

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  Figure 4. Specificity and sensitivity of the colloidal gold ICS. (A) Specificity of the colloidal gold ICS. The MEV, CPV, canine distemper virus (CDV), Aleutian mink disease virus (AMDV), and canine adenovirus (CAV) strains were tested by ICS. All specimens other than MEV and CPV resulted in two bands on the T line and C line. (B) Sensitivity test of the ICS. Different concentrations of MEV B strain (MEVB) subjected to MEV ICS (214–27 hemagglutination unit/100 μl, respectively). Similar results were obtained in three independent experiments by different operators (data not shown).