Natural-killer cell(NK)activity as determined by ~(51)Cr-and ~(125)I-UdR release assays a comparison / 中国免疫学杂志

Target cells K562 were labeled using two different isotopes,~(51)Cr and ~(125)I-UdR,for detecting NK activity of peripheral blood mononuclear cells in normal subjects.The NK activity was higher in ~(51)Cr release assay in comparison with ~(125)I-UdR release assay. After six-hour incubation,the percentage release of ~(51)Cr was around 60% whereas that of ~(125)I-UdR was only 30% in 20 hours. ~(125)I-UdR release could be enhanced by trypsin treatment.