Compact Epstein-Barr virus diagnosis based on a defined antigen mix and specific IgA.

An ELISA was evaluated to measure EBV-specific IgM, IgG and IgA using a test plate coated with a controlled mix of EA, VCA and EBNA. Using the IgM version, the multi-reactive surface reduced false-negative findings in cases of infectious mononucleosis (sensitivity 98%), but was confronted with polyclonal IgM responses (specificity 85% to 95% depending on the population). For the IgG version, a national research standard was involved, and in combination with the IgA estimation, a new diagnostic strategy became possible for chronic EBV infections and reactivations.

Multicenter evaluation of a novel quantification method for rubella and toxoplasmosis antibodies.

Antibody quantification by EIA is possible without a standard curve. Following the so-called alpha method only one test dilution is used, the resulting absorbance is corrected and the IU/ml will be calculated by means of a mathematical formula. This new kind of a single point measurement was evaluated in seven independent laboratories by comparison with commercial EIAs using a standard curve or a titer calibration line.

Single point quantification of antibody by ELISA without need of a reference curve.

A new method for the quantification of antibodies in the enzyme-linked immunosorbent assay is described. This procedure replaces titer determinations based on end-point dilution of the antibody under investigation. Here, the sample is tested in a single dilution and the optical density (OD) obtained is used in the equation log10 titer = alpha.

Technical improvements of a commercial ELISA to detect antibodies against bovine herpesvirus 1.

Prevention and control of the spread of IBR/IPV virus in cattle presumes exact diagnosis even with large sample collections. The requirements are fulfilled firstly by the application of the most sensitive testing methods for virus specific antibodies, such as the enzyme-linked immunosorbent assay (ELISA), and secondly by the introduction of bovine milk as a specimen for sampling. Data are presented demonstrating the application of a commercial ELISA system for evaluation of large sample collections and its optimization for this purpose.