Establishment of an Indirect ELISA Method for the Detection of the Bovine Rotavirus VP6 Protein.

Simple Summary: Rotavirus is one of the pathogens that cause diarrhea in calves. Bovine rotavirus poses difficulties in diagnosis and prevention due to its complex serology and large differences between strains, so the establishment of a rapid and effective detection kit has a wide range of applications for the early diagnosis and timely treatment of viral infections. In this study, we expressed the bovine rotavirus VP6 protein by a eukaryotic expression system, immunized BALB/c mice to collect serum, and established an indirect ELISA for VP6 protein. Our results showed that the prepared indirect ELISA has the advantages of good specificity and high sensitivity, which provides technical support for the effective detection and epidemiological investigation of bovine rotavirus at a later stage. The objective of this study was to develop an indirect ELISA utilizing a polyclonal antibody against bovine rotavirus (BRV) VP6 protein. To achieve this, pcDNA3.1-VP6, a recombinant eukaryotic expression plasmid, was constructed based on the sequence of the conserved BRV gene VP6 and was transfected into CHO-K1 cells using the transient transfection method. The VP6 protein was purified as the coating antigen using nickel ion affinity chromatography, and an indirect ELISA was subsequently established. The study found that the optimal concentration of coating for the VP6 protein was 1 μg/mL. The optimal blocking solution was 3% skim milk, and the blocking time was 120 min. The secondary antibody was diluted to 1:4000, and the incubation time for the secondary antibody was 30 min. A positive result was indicated when the serum OD450 was greater than or equal to 0.357. The coefficients of variation were less than 10% both within and between batches, indicating the good reproducibility of the method. The study found that the test result was positive when the serum dilution was 217, indicating the high sensitivity of the method. A total of 24 positive sera and 40 negative sera were tested using the well-established ELISA. The study also established an indirect ELISA assay with good specificity and sensitivity for the detection of antibodies to bovine rotavirus. Overall, the results suggest that the indirect ELISA method developed in this study is an effective test for detecting such antibodies. [ABSTRACT FROM AUTHOR]