[DMNH chemiluminescence of ingesting monocytes]

We have described a method to measure the chemiluminescence of stimulated monocytes, which necessitated only a few ml blood and thus make possible the investigation of clinical problems. The measurement of the chemiluminescence of monocytes is performed in a suspension of mononuclear leukocytes containing 40%-50% monocytes and 50%-60% lymphocytes. The preparation of this suspension requires a smaller blood volume than that of a suspension of pure monocytes. This method is possible because of the incapability of lymphocytes to produce chemiluminescence. A further important element of the described procedure is the fact that contamination of the mononuclear cell suspension with polymorphonuclear leukocytes, which show pronounced activity of oxidative metabolism and thus a high degree of chemiluminescence, is excluded. The application of 7 Dimethylamino-naphthalene-1,2-dicarbonic acid hydrazide (DMNH) as highly efficient chemiluminescent oxidant indicator and of the sensitive chemiluminescence measuring instrument Biolumat LB 9 500 permit the assessment of the chemiluminescence activity of monocytes in 10(5) cells. By varying the single components of the measuring approach (number of monocytes, number of ingesting particles, concentration of DMNH) the testing conditions were examined and a standard approach was determined. The average value of the chemiluminescence of phagocytosing monocytes in healthy adults during 30 min measuring time is 3.13 (S = 0.79) X 10(6) relative light units/10(5) cells. The point of maximum photone emission per unit in time is reached after 5-10 min.