2.4.3. Oxygen radical productionSpo

2.4.3. Oxygen radical production
Spontaneous and stimulus-induced oxygen radical production
in whole blood and of isolated neutrophils was evaluated using
Luminol-enhanced chemiluminescence and determined in an
automated LB96V Microlumat Plus Luminometer (EG & G Berthold,
Bald Wilberg, Germany), as described in detail previously. 6 Briefly,
1:100 in PBS-diluted blood or isolated neutrophils were added to
a 96-well microplate, either without stimulus, or in the presence of
a receptor-independent (phorbol 12-myristate 13-acetate, PMA) or
receptor-dependent (serum-treated zymosan particles, STZ) stim-
ulus. Luminol was added to each well to start the chem-
iluminescence reaction. Each measurement was carried out in at
least four replicates. Chemiluminescence was determined every 145 s at 37
? C for 1 h. Luminescence was expressed as relative light
units per second (RLU/s). Data were analyzed with Winglow soft-
ware (EG & Berthold). After subtraction of background signal, the
signal intensity in whole blood samples was corrected for the
neutrophil population count.