Nitroblue tetrazolium (NBT) Reduction Test on Canine Neutrophils

Abstract

Nitroblue tetrazolium (NBT) reduction test on canine neutrophils was studied by a slightly nodified Gifford's method. Though percentage of positive cells was evaluated in the original method, the authors classified each cell on the basis of formazan deposit pattern and calculated a score. The NBT test result was evaluated by positive cell percentage with score. In endotoxin stimulated NBT test, the score was remarkably elevated as compared with positive cell percentage. These results suggested that the NBT test may be indicative of reduction capacity of neutrophils when indicated by positive cell percentage as well as the scores. Normal canine neutrophils showed a mean positive rate of 68.7% and a mean score of 217.8 in resting NBT test, 78.7% mean positive rate and 281.4 mean score in 50 μg/ml endotoxin stimulated NBT test, and 81.3% mean positive rate and 346.6 mean score in 100μg/ml endotoxin stimulated NBT test.