A Microtitre Technique for the Assay of Malignant Catarrhal Fever Virus and Neutralising Antibody

Abstract

A microtitre technique for the quantal assay of a cell-free strain of malignant catarrhal fever virus was developed, using serially passaged bovine embryonic kidney cells. End-points were determined after 12 days’ incubation and the mean titre recorded for a single virus stock stored at −70°C over a six-month period was 105·5±0·2 (SD). In neutralisation tests serum/virus mixtures were best held at 37°C for 1 h in microtitre trays before the addition of cells; assays were highly reproducible, figures of 101·5±0·2 being obtained for a single reference serum.