Semiquantitative dot‐blot immunogold assay for specific detection of white spot syndrome virus

Abstract

A dot-blot immunogold assay (DBIA) was developed to detect white spot syndrome virus (WSSV) using the polyclonal antibody VP26 (anti-VP26). The anti-VP26 was immobilized on gold nanoparticles (Ab-AuNPs), and a nitrocellulose membrane was used as a detection pad. When the target WSSV bound to the Ab-AuNPs a reddish dot appeared on the surface of the membrane used within 2-5 Min, which could be seen with the naked eye. The test was able to detect WSSV at concentrations as low as 10 copies μL of WSSV. The DBIA developed had good specificity, and the colloidal gold probe can be applied within 2-3 days when stored at 4 °C. For real sample analysis, the DBIA was applied to samples of seawater used for shrimp cultivation without sample preparation. The results indicate that sample 1 showed a positive result, whereas samples 2 and 3 produced negative results. Then, samples 2 and 3 were spiked with WSSV for method validation. To confirm the performance of the DBIA developed, polymerase chain reaction (PCR) was conducted and the PCR results were the same as those found by the DBIA. Therefore, the DBIA developed could be applied for WSSV detection in real water samples.

Development of a Rapid Gold Nanoparticle-Based Lateral Flow Immunoassay for the Detection of Dengue Virus

“…This test measured the stability of the conjugates in saline solution (20% NaCl) where a considerable difference was not observed between the stability of the conjugate with 3 and 6 µg/mL (GAT values less than 0.02), indicating that from 3 µg/mL, the surface of the AuNPs has an antibody monolayer that prevents aggregation. These tests have been performed by other authors in order to determine the minimum concentration of antibodies for the coating of AuNPs [ 43 , 44 ]. Therefore, the biosensor that was used to assemble the LFA was 3 µg/mL.…”