Standard plaque assays to determine infectious viral titers can be time consuming, are not amenable to a high volume of samples, and cannot be done with viruses that do not form plaques. As an alternative to plaque assays, we have developed a high-throughput titration method that allows for the simultaneous titration of a high volume of samples in a single day. This approach involves infection ...

pepsin (Dawson and McFarlane, 1948 ; Peter and Stoeckenius, 1954). For the purpose of finding out any enzyme to affect the surface structure of vaccinia virus under less radical conditions than with pepsin (pH 3.0), attempts were made to test various enzymes for the effect on the infectivity of the virus. Virus suspension was prepared from the homogenate of infected chorioallantoic membranes (C...

VALIDATION OF FAO/IAEA/PANAFTOSA ELISA KIT FOR THE DETECTION OF ANTIBODIES AGAINST FOOTAND-MOUTH DISEASE VIRUS IN VENEZUELA. A liquid phase blocking ELISA (LPBE) supplied by FAO/IAEA/PANAFTOSA has been evaluated for the qualitative and quantitative detection of specific antibodies to "O" and "A" serotypes of foot-and-mouth disease (FMD). A total of 240 bovine sera were analyzed. 120 sera from n...

Using the microtiter system, titration of Newcastle disease virus infectivity and neutralizing antibodies was carried out in chicken embryo fibroblasts grown in "U" or flat-bottomed plates. Infectivity was detected by a combined hemadsorption-hemagglutination method. Inhibition of that reaction indicated the presence of neutralizing antibodies. A 24-h microneutralization test was developed and ...

A rapid and simple technique for the detection of latent RNA tumor viruses has been described. It is based on phenotypic mixing between the latent agent (s) and a nondefective strain of RSV used as indicator virus. Most of the embryos from two different chicken lines tested so far contain such agents. According to their host range and serological properties they belong to subgroup E. The phenot...

To prevent transmission in Ebola Virus Disease (EVD) outbreaks, it is recommended to disinfect living things (hands and people) with 0.05% chlorine solution and non-living things (surfaces, personal protective equipment, dead bodies) with 0.5% chlorine solution. In the current West African EVD outbreak, these solutions (manufactured from calcium hypochlorite (HTH), sodium dichloroisocyanurate (...

A series of 19 different primary and serial tissue cultures were investigated for their sensitivity to virulent or attenuated rubella virus (RV). Primary guinea pig tissues, a serial passage of baby hamster kidney, and primary human amnion were comparable to African green monkey kidney tissue cultures in their sensitivity. In general, primary human tissues were relatively insusceptible to the G...

A rapid, simple, and accurate Modified Counter Current Immuno-electrophoresis (MCCIE) technique was developed and compared with the Reverse Passive Heamagglutination Assay (RPHA) for the titration of HPS virus. The MCCIE test had 100% correlation with the conventional RPHA and correctly titrated 116 samples which were already titrated with RPHA. Instead of horizontal electrophoresis chamber use...

OBJECTIVE To evaluate the ability of small interfering RNAs (siRNAs) to inhibit in vitro viral replication and gene expression of feline coronavirus (FCoV). SAMPLE Cell cultures of Crandell-Rees feline kidney cells. PROCEDURES 5 synthetic siRNAs that each targeted a different region of the FCoV genome were tested individually and in various combinations for their antiviral effects against 2...