Development and characterization of a lateral flow immunochromatographic assay test strip for rapid detection of rubella virus antigen

Rubella is still considered a dangerous infectious disease, especially for pregnant women. The symptoms of rubella can be similar to those of other illnesses. Therefore, an early and accurate diagnosis of the rubella virus will help doctors make a reasonable treatment plan. This study presents the development and characterization of a novel lateral flow immunochromatographic assay test strip for rapid recognition of rubella virus antigen. Rabbit polyclonal antibodies against the rubella virus were purified with a purity of 95%. Optimal conditions for the production of the main components of a test strip were determined. Anti-rubella virus polyclonal antibodies were physically adsorbed onto the star-shaped gold nanoparticles at the optimal concentration of 1.0 μg/ml at 25°C for 30 min. The amounts of antibody per conjugate pad and immobilized on the test line were 0.2 μg/pad and 4.5 μg/cm, respectively. The properties of the test strip were characterized by testing mock clinical specimens. Reproducibility and repeatability were achieved at 100%. The limit of detection of the test strip was determined to be as low as 5 × 105 virus particles/mL. The test strip did not cross-react with six different potential interfering pathogens. The sensitivity and specificity of the test strip were determined by testing with 400 mock clinical samples and reached 99.5% and 98.5%, respectively. The Kappa statistics (k coefficient = 0.98) showed very good agreement between the generated test strip and real-time PCR results. According to the findings, the test strip can be used as an additional rapid test tool for the detection of the rubella virus.