Quantitation of immunoglobulins in ovine sera and secretions by laser nephelometry. Comparison with the radial immunodiffusion (RID) technique.

In twenty-five ovine body fluids (serum, lung fluid and cerebrospinal fluid), the concentrations of IgG1I, IgG2, IgM and IgA were determined by laser nephelometry and radial immunodiffusion (RID). When nephelometric assays are carried out, antisera free from any turbidity are essential. Methods ensuring that goat and rabbit anti-sera will satisfy this requirement are described in the present paper. When sheep immunoglobulins were measured by laser nephelometry, adequate and reproducible results were obtained, comparable with those obtained by RID. Advantages of the nephelometric method include the speed of assay and its sensitivity, allowing precise determination of the very low concentrations of immunoglobulins in CSF.