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@#Abstract：Objective To develop a colloidal gold immunochromatographic strip ⁃ based method for the rapid detection of Zika virus（ZIKV）NS1 antigen. Methods The gold nanoparticles modified with the anti⁃ZIKV NS1 monoclonal antibody as the detection probe were coated on the glass ⁃fiber pad. The anti ⁃ZIKV NS1 monoclonal antibody and the goat anti ⁃mouse polyclonal antibody were immobilized on a nitrocellulose membrane as the test line and the control line，respectively. In order to achieve critical results，the ratio of the optical density （OD）of the test line to that of the control line was compared. Serial diluted ZIKV NS1 standard antigen was applied to evaluate sensitivity of the immunoassay. The culture supernatant and serum samples for arboviruses（ZIKV，Dengue virus, Japanese encephalitis virus and Chikungunya virus） were utilized to demonstrate the specificity of the method. Results The detection result could read by naked eyes within 20 minutes. The visual cut ⁃off level for the test strip was achieved at 100 ng/mL of the Zika virus NS1 standard antigen. No cross⁃reactions with Dengue virus，Japanese encephalitis virus and Chikungunya virus were observed. The strip could remain good stability within 36 weeks whether stored in 4 ℃ or room temperature（22-25 ℃）. Conclusion Apart from stability， the method was convenient，rapid and specific for ZIKV NS1 antigen，which showed a promising potential in the point of care test and the screening test.
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Objective To prepare the specific monoclonal antibodies(mAb) of Mycoplasma pneumonia(MP) and to establish a colloidal gold rapid detection method of MP by using mAb .Methods The nasopharyngeal swab samples were collected from chil‐dren patients with acute respiratory tract infection ,separated and cultured and performed the MP identification ,MP antigen was pu‐rified ,mAb of MP was prepared ,then the MP colloidal gold test strip was established by using MP mAb .The throat swab sample was collected from the patients with suspected MP infection and detected by using the fluorescent quantitative PCR and colloidal gold test strip .The detection results were observed and statistically analyzed .Results MP strain was successfully isolated and inac‐tivated ,the MP antigen was purified .The mouse was immunized by using this antigen ,19 strians of mAb against MP were prepared by using the hybridoma technique .Among them ,2 strains of mAb with high titer and good specificity(MP‐5 and MP‐19) were se‐lected as the raw materials for preparing the MP colloidal gold rapid test strip .The lowest detection limit was 20 ng .The clinical samples were detected by using the MP colloidal gold rapid test strip and fluorescent quantitative PCR .The results showed that the sensitivity of MP colloidal gold rapid test strip by using this established method was 88 .2% and its specificity was 82 .6% .Conclu‐sion specific mAbs against MP is prepared and the colloidal gold rapid detection method is preliminarily established which provides the help for rapid diagnosis in the patients with MP infection .
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Objective To explore the effect of a novel colloidal gold immunochromatographic test strip for detection of group B streptococci (GBS).Methods A total of 202 cases of swab of vagina or neck of uterus were collected,and they were detec-ted by novel strip and control strip to evaluate their clinical applications.Results Sensitivity of novel strip was about 105 CFU/ml and the detection time was about 5 to 8 minutes,and it showed better sensitivity and shorter detection time com-pared with control strip.In the 202 cases of clinical samples,the detection results of 197 cases were in consistent with the control strip,however,the detection results of 5 cases were not in consistent.The positive coincidence rate and negative coin-cidence rate were 97.5% and 97.54% respectively,and the total coincidence rate and Kappa value were 97.52% and 0.948 respectively.The consistency test showed no significant difference between this strip and control strip.Conclusion This method was a effective technology for diagnosing of infection caused by GBS,and had high value in clinical application.
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PURPOSE: To evaluate the feasibility for gold immunochromatographic assay (GICA) in rapid detection of influenza virus A infection. MATERIALS AND METHODS: Seventy-three patients were enrolled. All patients contributed nasopharyngeal secretions and paired serum samples. Nasopharyngeal secretions was used for colloidal gold immunochromatographic rapid assay for influenza A virus immediately after the collection of specimen. Paired serum samples were used for the hemagglutination inhibition assay at the Centers for Disease Control and Prevention influenza network laboratory in Beijing. RESULTS: Compare GICA test to hemagglutination inhibition (HI) assay, the Kappa value was 0.402 and the p value in the paired chi2 test was higher than 0.05. Therefore, the difference was not statistically significant. The sensitivity of GICA was 50.0% and the specificity was 90.2%, and the negative predictive value was 90.2%. CONCLUSION: The sensitivity for Influenza A antigen detection by using GICA is relatively low, the specificity is relatively satisfactory.