In vitro detection of human reagins by double layer leucocyte agglutination: method and controlled blind study.

The double layer leucocyte agglutination method for assaying reagins is described in detail. Only polymorphonuclear leucocytes and not lymphocytes are found to participate in the reaction. Non-specific agglutination can be kept at a minimum by working at 37° instead of at room temperature. In a carefully controlled blind study the test was found to corroborate clinical findings in 80 per cent of the cases. Simple methods are given for preparing homogeneous suspensions of lymphocytes and for a rapid fluorescent differentiation between unfixed lymphocytes and polymorphonuclear cells by means of acridine orange.