Normal values for the nitroblue tetrazolium test (NBT. test).

The mean count of positive neutrophils in the NBT test was found to be 10.9 + 1.2 SE (29). The mean count for neutrophils stimulated with heat killed bacteria was 51.6 + 2.2 SE (29). The values are essentially the same as those reported for other populations and laboratories. The number of positive cells was found to decrease logarithmically with time. This relationship forms a basis for the development of a normogram which can be used to interpret NBT test results obtained from blood which has been stored for several hours.