Development of a colloidal gold immunochromatographic strip with enhanced signal for the detection of bovine parvovirus

by Selleckchem | Aug 17 2023

Bovine parvovirus (BPV) is a pathogen responsible for respiratory and digestive tract symptoms in calves and abortion and stillbirth in pregnant cows. In this study, we developed a colloidal gold immunochromatographic (GICG) strip with an enhanced signal for detecting BPV according to the double-antibody sandwich principle and an enzyme-based signal amplification system to amplify the signal. This system utilizes horseradish peroxidase reacting with a substrate solution containing 3,3',5,5'-tetramethylbenzidine and dextran sulfate to obtain insoluble blue products on the test and control lines. We optimized different reaction conditions, including the amount of monoclonal antibodies (mAbs), pH of the colloidal gold solution, coating solution, blocking solution, sample pad treatment solution, antibody concentration in the control line, and antibody concentration in the detection line. The sensitivity of the signal-enhanced GICG strip showed that the minimum amount for detecting BPV was 102 TCID50, 10 times higher than that of the traditional GICG strip. The results of the specificity test showed that the signal-enhanced GICG strip had no cross-reactivity with BRV, BVDV, or BRSV. The results of the repeatability test showed that the coefficient of variation between and within batches was less than 5%, showing good repeatability. Moreover, for validation, PCR and the signal-enhanced GICG strip were used to detect 280 clinical bovine fecal samples. The concordance rate compared with PCR was 99.29%. Hence, the developed strip exhibited high sensitivity and specificity for the detection of BPV. Therefore, this strip could be a rapid, convenient, and effective method for the diagnosis of BPV infection in the field.

Comments:

The study you mentioned describes the development of a colloidal gold immunochromatographic (GICG) strip with an enhanced signal for detecting Bovine Parvovirus (BPV). The strip operates on the double-antibody sandwich principle and utilizes an enzyme-based signal amplification system to enhance the detection signal. The system involves horseradish peroxidase reacting with a substrate solution containing 3,3',5,5'-tetramethylbenzidine and dextran sulfate, which results in the formation of insoluble blue products on the test and control lines of the strip.

The researchers optimized various reaction conditions during the development process. These conditions included the amount of monoclonal antibodies (mAbs), the pH of the colloidal gold solution, the coating solution, the blocking solution, the sample pad treatment solution, the antibody concentration in the control line, and the antibody concentration in the detection line.

The sensitivity of the signal-enhanced GICG strip was evaluated, and it was found to be capable of detecting a minimum amount of 102 TCID50 of BPV. This sensitivity was 10 times higher than that of the traditional GICG strip. Additionally, the specificity of the strip was tested, and it showed no cross-reactivity with other pathogens such as Bovine Rotavirus (BRV), Bovine Viral Diarrhea Virus (BVDV), or Bovine Respiratory Syncytial Virus (BRSV).

Repeatability tests were conducted to assess the consistency of the strip's performance. The coefficient of variation between and within batches was found to be less than 5%, indicating good repeatability.

To validate the strip's effectiveness, 280 clinical bovine fecal samples were tested using both the strip and PCR (Polymerase Chain Reaction). The concordance rate between the strip and PCR results was determined to be 99.29%.

In conclusion, the developed signal-enhanced GICG strip demonstrated high sensitivity and specificity in detecting BPV. This strip has the potential to serve as a rapid, convenient, and effective method for diagnosing BPV infection in the field.