Europium-labelled target cells in an assay of natural killer cell activity

The use of a new marker for labelling cells used as targets for natural killer cells is described. The human erythroleukaemic cell line K-562 was used as target. The cells were labelled with europium diethylenetriaminopentaacetate (EuDTPA) chelates. The detection of the released marker is based on time-resolved fluorometry. The results obtained show that the method is sensitive, specific and rapid. The high specific activity of the marker and...