Quantification of neutrophil chemotaxis: a comparison of stereological and 51Cr-labelling methods

A stereological method has been used to estimate the number of migrated polymorphonuclear leukocytes in a multipore filter assay. The estimates have been compared to those obtained with conventional 51Cr-labelling methods. The precision of the estimates in individual subjects with the two methods was similar, and in both cases the contribution to the interindividual variance made by the methods was small compared to the biological variance. However, the 51Cr-labelling method resulted in a significant reduction in the fraction of neutrophils that migrated as well as a delay in the chemotactic response. Optimal assay conditions with regard to sample size, cell concentration, incubation time and chemoattractant fMLP concentration have been established for the stereological method and the virtues of the two techniques discussed.