Integrating immunomagnetic bead enrichment with immunochromatography for the detection of influenza A virus

Abstract

Objective To establish a novel method by integrating immunomagnetic bead enrichment with immunochromatography for the detection of influenza A virus. Methods The immunomagnetic beads were prepared by using EDC/NHS method and then coupled with monoclonal antibodies against influenza A virus. A direct immunomagnetic beads-based immunochromatography for the detection of influenza A virus was developed by using double-antibody sandwich method and immunochromatography, which was further combined with immunomagnetic separation to establish the novel integrated method of immunomagnectic bead enrichment and immunochromatography. Clinical throat swab samples collected from patients with influenza A virus infection and healthy subjects were analyzed by the novel method and the results were compared with those by using the conventional colloidal gold immunochromatography to evaluate the specificity, sensitivity and positive coincidence rate of this established method. Results The direct immunomagnetic beads-based immunochromatography and the colloidal gold immunochromatography showed no significant differences in specificity and sensitivity and could be used to identify influenza A virus-positive samples with cycle threshold (Ct) values less than or equal to 22 obtained by real-time PCR assay. The integrated method could identify positive samples with Ct values less than or equal to 28, indicating that the novel method was more sensitive. Conclusion The novel method by integrating immunomagnetic bead enrichment with immunochromatography was successfully established and suitable for the rapid and on-site detection of influenza A virus. Key words: Influenza A virus; Immunomagnetic beads; Immunochromatography; Rapid detection