A SIMPLE FLOW-CYTOMETRY ASSAY USING DIHYDRORHODAMINE FOR THE MEASUREMENT OF THE NEUTROPHIL RESPIRATORY BURST IN WHOLE-BLOOD - COMPARISON WITH THE QUANTITATIVE NITROBLUETETRAZOLIUM TEST

The neutrophil respiratory burst is essential for the host's ability t o kill ingested microorganisms. Several flow cytometric assays have re cently been developed to measure this process. These assays are largel y unvalidated. In this study a whole blood flow cytometry assay using dihydrorhodamine 123 (DHR) as a substrate was compared with the quanti tative nitrobluetetrazolium (NBT) test, an accepted measure of the ear liest events in the respiratory burst. Because whole blood is used, th e new assay is quicker and simpler than existing flow cytometry assays . Specimens as small as 0.1 ml can be used which makes the assay ideal for use in neonates and young children. There was a high degree of co rrelation between the DHR assay and the quantitative NET test (r(s) = 0.76, P < 0.01). It is concluded that the whole blood DHR assay is an accurate and sensitive measure of the respiratory burst. (C) 1998 Else vier Science B.V. All rights reserved.