A comparison of the kinetics of the macrophage electrophoretic mobility (MEM) and the tanned sheep erythrocyte electrophoretic mobility (TEEM) tests.

In this study the macrophage electrophoretic mobility (MEM) test was modified by using tanned sheep erythrocytes in place of guinea pig peritoneal macrophages as the indicator cells of lymphocyte sensitization to antigens. This modification is named the tanned sheep erythrocyte electrophoretic mobility (TEEM) test, and a comparison of the kinetics of the two systems allowed the following conclusions to be made: 1) Treatment of freshly drawn sheep red blood cells with a concentration of 1/40,000 tannic acid produced optimum results in the TEEM test. 2) Lymphocyte-antigen and lymphocyte-number response curves show similarity in the two test systems. 3) A plateau response with slowing factor is achieved at a lower dilution in the TEEM test than in the MEM test. 4) Whilst similarity in the first stage reaction was found in the two systems, in the second stage of the test (at 37 degrees C) tanned sheep red cells gave a plateau response after 45 min instead of the 60 min found in the MEM test. 5) The two slowing factors showed similar gel filtration patterns with molecular weights between 13,000 and 15,000 daltons, and had equivalent activity in both test systems. 6) The disadvantages of the guinea pig macrophage as an indicator cell are discussed. 7) The TEEM test seems simpler to perform than the MEM test and may be widely applicable in clinical immunology for the estimation of lymphocyte sensitization.