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Updated: Sep 6, 2026
Flow Cytometry-based Assay for the Monitoring of NK Cell Functions
Published on: October 30, 2016
A novel enhanced green fluorescent protein (EGFP)-K562 flow cytometric method for measuring natural killer (NK) cell
Wannee Kantakamalakul1, Jiraporn Jaroenpool, Kovit Pattanapanyasat
1Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. siwkk@mahidol.ac.th
Abstract:
Enhanced green fluorescent protein (EGFP) was stably expressed in human erythroleukaemia K562 cells (EGFP-K562) and used as target cells for measurement of natural killer (NK) cell cytotoxicity by flow cytometry. The compromised EGFP-K562 target cells were stained with propidium iodide (PI) and showed dual (green-red) fluorescent. Although the kinetic study demonstrated that the optimal incubation time for the assay was 4 h, a 2-h incubation period also gave comparable results. This new technique correlated strongly with the standard chromium (51Cr) release assay at the correlation coefficients of 0.87 and 0.89 at p-value <0.001 for 2- and 4-h incubation times, respectively. The EGFP-K562 stable cell line provides a novel method to measure NK cytotoxicity by flow cytometry without pre-staining or pre-labeling target cells.
