A novel colloidal gold immunochromatography assay strip for the diagnosis of schistosomiasis japonica in domestic animals

Background:Schistosomiasis remains a major public health concern in China and an epidemiological survey has revealed that schistosome-infected bovines and goats are the main transmission sources for the disease.Therefore,development of a sensitive technique for the diagnosis of schistosomiasis in domestic animals is necessary.Method:A novel colloidal gold immunochromatography assay(GICA)strip was developed for detecting Schistosoma japonicum in domestic animals.The colloidal gold was conjugated with recombinant streptococcal protein G(rSPG).As the test and control lines,the schistosome soluble egg antigen and rSPG,respectively,were blotted on nitrocellulose membrane.Results:The lowest detectable serum dilution was 1∶640 for schistosome-infected buffaloes.The cross-reaction rate of GICA was 14.29%with Paramphistomum sp.in buffaloes,16.67%with Haemonchus sp.in goats,and 33.33%with Orientobilharzia sp.in goats.These results were slightly lower and similar to those obtained through ELISA.Moreover,the strips for detecting S.japonicum in mice,rabbits,buffaloes,and goats showed high sensitivity(100.00%,100.00%,100.00%,and 100.00%,respectively)and specificity(100.00%,100.00%,94.23%,and 88.64%,respectively).And the sensitivity or specificity of the GICA strips did not present any significant differences after storage for 12 months at room temperature.When compared with ELISA,the GICA strips exhibited similar sensitivity and specificity in the diagnosis of schistosomiasis in mice,rabbits,buffaloes,and goats.Besides,only 5μl of serum are required for the test and the detection can be completed within 5 min.Conclusion:This study is the first to develop a GICA strip using gold-rSPG conjugate for the diagnosing of schistosomiasis in domestic animals,and preliminary results showed that the developed strip may be suitable for large-scale screening of schistosomiasis in endemic areas.

Immune fluorescence test strips based on quantum dots for rapid and quantitative detection of carcino-embryonic antigen

At present,many researchers focused on the point-of-care testing（POCT）,a method of disease markers detection without large-scale instruments and specialized persons.However,most POCT diagnostic methods were suffered from poor detection sensitivity or inefficiency in quantitative detection.Herein,we developed a newly QD-immune fluorescence test strips（QD-IFTS） based on quantum dots（QDs） as the fluorescence nanocarrier to prepare the immune fluorescence probes in the classical immunochromatography detection system for sensing carcino-embryonic antigen（CEA）,a kind of glycoprotein produced by intestinal tissue and a broad spectrum of tumor marker for cancer diagnosis.And we designed a homemade strips fluorescence reader for detection of fluorescence intensity of QDs on the QD-IFTS.Under the optimized reaction conditions,chromatographic time of the newly QD-IFTS was only25 min,sample volume of the newly QD-IFTS was only 40 m L and the LOD of the newly QD-IFTS was 0.72 ng/m L.In addition,the efficiency and robustness of the newly QD-IFTS were confirmed by successfully application in 300 clinical serum samples,and the results revealed great potential in clinical POCT of other biomarkers.