1. The agglutination titres for sheep and for horse erythrocytes of 100 normal sera and twenty-seven glandular fever sera have been determined.2. The results of the sheep-cell agglutination tests on normal sera differed considerably from those of Stuart, Burgess, Lawson & Wellman (1934) whose technique was used. The reason for this difference was not determined. It was thought to have some bearing upon the interpretation of sheep-cell agglutination tests in the diagnosis of glandular fever.3. Although in the glandular fever sera the horse-cell titre was usually higher than the sheep-cell titre, the normal range for horse cells was also higher, and in the diagnosis of glandular fever there did not appear to be any advantage in using horse cells instead of sheep cells.4. The value of absorption tests in the diagnosis of glandular fever is discussed and a new technique described which has practical advantages over other methods although it does not embody any important new principles.5. Of 300 normal sera examined by this technique, five contained small amounts of an antibody indistinguishable from glandular fever antibody and ten others contained a sheep-cell agglutinin apparently, though not certainly, different from any yet recognized in human serum.6. A comparison of the results of the two tests on thirty-one samples of glandular fever serum showed the absorption test to be a more sensitive diagnostic test for glandular fever than the ordinary sheep-cell agglutination test.
The Sensitivity and Specificity of a Red Blood Cell Agglutination D-Dimer Assay for Venous Thromboembolism When Performed on Venous Blood