Lymph nodes (Ln) are the preferred samples for virus isolation and detection. Inthe present study, carcass and visceral Ln of apparently healthy cattle were screened for the presence of bovine herpes virus type 1 (BHV-1) and bovine ephemeral fever virus (BEFV) antigens. A total of 198 Ln (114 carcasses Ln and 84 visceral Ln) were collected. Lymph node homogenates were assayed by agar gel precipitation test (AGPT), rapid Staphyloccocal protein A (SPA) agglutination test and Dot-ELISA. The overall results revealed that BHV-1 antigens were detected in 43.9%, 56.1% and in 68.4% of carcass Ln, and in 29.8%, 47.6% and 57.1% of visceral Ln collected from slaughtered cattle by AGPT, SPA agglutination test and Dot-ELISA respectively. On the other hand, BEFV antigens were detected in 5.3%, 38.6% and 52.6% of carcass Ln, and in 6%, 41.7% and 54.8 % of visceral Ln collected from slaughtered animals by AGPT, rapid SPA agglutination test and Dot-ELISA respectively. The results showed high percentage of positive samples with SPA agglutination test and Dot- ELISA in comparison to AGPT for both BHV-1 and BEF.

Studies were conducted to determine the utility of lysate antigens for rapidevaluation of the local entero-3 vaccine, antigens were prepared from cell culturesinfected with bovine rota virus (BRV) and bovine corona virus (BCV) as well asfrom Enterotoxigenic E. coli strain K99. Prepared antigens were tested with fieldserum samples collected from both late pregnant entero-3 vaccinated cows and their offsprings using different serological assays including: microagglutination test,indirect ELISA and immunofluorescent antibody technique. Results of this endeavorwere correlated to that of the standard virus neutralization test. The locally preparedantigens were proved useful for vaccine evaluation. Moreover, these antigens arerecommended for both detection and assessment post vaccination or post infection of sero-conversion against BRV, BCV and E. coli.

kills Brucella cells by causing lysis of the membrane, so the phenol-heat killed brucella antigen may lake specificity as a result of destruction the majority of proteins in the cell wall. Accordingly, attention was directed to produce antigen using binary ethylene imine as an inactivator. The produced antigen showed high specificity in detecting Brucella abortus and Brucella melitensis-infected animals, but sensitivity was not affected in comparison with the standard Rose Bengal antigen. In Enzyme immunotransfer blot (EITB), phenol–heat killed brucella cells showed only 3 bands (37.375, 23.47 and 7.83 kDa) that denotes denaturation for at least 6 bands whereas binary inactivated brucella cells showed similarity with non-treated ones