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Background and Objective: Hydatidosis is a chronic, zoonotic worldwide infection which induced by larval stage of Echinococcus worm. This study was done to assessment the pure and B hydatid cyst fluid antigens for the serological diagnosis of human hydatidosis. Methods: In this descriptive laboratory study, infected liver with Hydatid cyst were obtained from Tehran's slaughterhouses to prepare cyst fluid in different stages. After draining and purifying the cyst fluid, it was centrifuged and subsequently concentrated. Specificity and sensitivity of sera samples including hydatidosis (n=60), worm parasites (n=55), fascioliasis (n=35), toxocariasissera (n=20) and negative control (n=35) were tested by Counter Immunoelectrophoresis (CIEP), ELISA and Dot ELISA methods. Results: Specificity and sensitivity of pure antigen of hydatid cyst using CIEP method was 68.9% and 86.7%, respectively. Specificity and sensitivity of B-antigen using CIEP method was 87.8% and 83.3%, respectively. Specificity and sensitivity of pure antigen of hydatid cyst using ELISA method was 76.7%, and 93.3%, respectively. Specificity and sensitivity of B-antigen using ELISA method was 96.7% and 88.3%, respectively. Specificity and sensitivity of pure antigen of hydatid cyst using Dot ELISA method was 83.3% and 100%, respectively. Specificity and sensitivity of B-antigen using Dot ELISA method was 100% and 98.3%, respectively. Conclusion: B-antigen using Dot ELISA method is the most suitable serological test for the diagnoses of hydatid test.

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Background and Objective: Enterotoxigenic Escherichia coli (ETEC) are the most common agent which causes diarrhea, worldwide. ETEC is colonized along the cells and then producing heat-labile (LT) and heat-stable enterotoxigenic which enter into intestinal epithelial cells and causes water and electrolyte loss from intestinal epithelial cells and eventually cause diarrhea.This study was done to detect the heat-labile toxin in Enterotoxigenic Escherichia coli using PCR-ELISA technique. Methods: In this descriptive study, DIG-labeled PCR products were bounded to streptoavidin-coated wells of a microtiter plate and detected by anti-DIG–peroxidase conjugate. The biotin-labeled internal probe was used for verification of PCR products. Results: Heat-labile toxin was detected by PCR-ELISA method. The sensitivity of heat-labile toxin was 1.9 ng. This method did not cross-react with bacteria from this variety. Conclusion: PCR-ELISA method is 100 times more sensitive than conventional PCR method and due to lack of agarose gel and electrophoresis device it can be a good alternative to traditional method.