Imaging-based, non-radioactive measurements of natural killer cell activity provides comparable results as classic chromium release assays but with fewer cells and less labor

Introduction Natural Killer Cell activity has traditionally been assessed by detecting the lysis of tumor cells in The Chromium Release assay. This classic assay relies on radioactive labels, is laborious, and requires substantial quantities of patient blood. Moreover the Chromium Release assay provides low signal to noise ratios. We have developed an assay that can visualize individual target cells to detect cytolytic activity within a high signal to noise range, without involving radioactivity, via high-throughput imaging. We also developed a miniaturized version of this assay to measure NK activity with one tenth of the blood needed for a classic Chromium Release assay, and with less labor.