The chemiluminescence (CL) microanalysis of the oxidative burst of phagocytes in whole blood is described. Several types of activators (opsonized zymosan, rice starch grains, phorbol myristate acetate, calcium ionophore A23187 and N-Formyl-Met-Leu-Phe) were tested and compared using different volumes of whole blood in the photometric cuvette. Other factors influencing the whole blood CL (storage time of blood samples, temperature of reaction mixture) were also evaluated in the study. It was found that only small volumes of whole blood are needed for the analysis: up to 2 ml and 5 ml when opsonized zymosan or phorbol myristate acetate and calcium ionophore are used as activators. Five ml are also effective for N-Formyl-Met-Leu-Phe, but larger volumes can be also used. Under such circumstances, the CL of whole blood is derived almost exclusively from the neutrophil activity. Estimation should be performed 1 hour after blood collection at temperatu re of 34 °C–40 °C. The CL emission should be measured for 60 minutes after activation with opsonized zymosan o r starch grains, 30 minutes after activation with N-Formyl-Met-Leu-Phe; a shorter period is sufficient for phorbol myristate acetate and calcium ionophore. The CL micromethod described provides a fast and sensitive tool for determination of metabolic activity of phagocytes in the microlitre range of whole blood.

        Key words: phagocytes, chemiluminescence, human whole blood, oxidative burst.