QUANTIFICATION OF SERUM TOTAL IGE CONCENTRATION IN DOGS BY USE OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY CONTAINING MONOCLONAL MURINE ANTI-CANINE IGE

A method for quantification of serum total IgE concentration in dogs b y use of an ELISA containing monoclonal mouse anti-canine IgE was deve loped. Microtitration plates were coated with monoclonal mouse anti-ca nine IgE. Test sera and reference serum dilutions were added, followed by biotinylated monoclonal mouse anti-canine IgE. Avidin-alkaline pho sphatase conjugate was added, and color development was measured spect rophotometrically, using a microtitration plate reader. Quantitative r esults were obtained by assigning to a reference serum a value of 100 IgE units/ml. Asorbance values of unknown samples were converted into IgE units by comparison with a standard curve generated by measurement of reference serum dilutions. Intra- and interassay coefficients of v ariation were 5 and 7%, respectively, and assay sensitivity was 1 U/ml . The assay was used to establish a normal range for total IgE concent rations in 30 healthy dogs. Total IgE concentration in healthy dogs fo llowed a skewed distribution and ranged from < 1 to 91.2 U/ml, with a geometric mean value of 7.1 U/ml. The IgE concentration was remarkably stable in serum samples subjected to 25 freeze/thaw cycles or incubat ion at approximately 25 C (room temperature) for up to 10 days. Compar ison of total IgE concentrations in 23 serum samples assayed by use of double-overlay radial immunodiffusion and ELISA yielded correlation c oefficient of 0.94. Comparison of the reference serum standard curve w ith serial dilutions of a purified IgE solution of known concentration yielded a range of values for the IgE unit of 0.7 to 2.0 mu g