nk 92 mi cell line  (ATCC)

Journal: bioRxiv

Article Title: A Cellular Cytotoxicity Assay using Ready-to-Thaw Target Cells without Washing Steps

doi: 10.64898/2026.01.21.700863

Figure Lengend Snippet: Toxicity of different concentrations of the cryopreservation medium STEM-CELLBANKER ® EX (SCB) towards K562 cells, primary NK cells, and NK-92 cells; cell viability was assessed via flow cytometry after 24 h incubation. A: Relative viability of K562 cells incubated with 0–100% SCB at 37°C and room temperature (RT) (n = 3 independent experiments, each 1 technical replicate); statistical analysis: two-way ANOVA with Tukey post hoc test within RT and 37°C groups. B: Relative viability of primary NK cells with 0–100% SCB at RT, 37°C, and 37°C + 500 U/mL IL-2 (left, n = 1 experiment, 1 technical replicate; no statistics performed) and with 0–25% SCB at 37°C (right, n = 2 donors/experiments, each 3 technical replicates); statistical analysis: two-way ANOVA with Tukey post hoc test. C: Relative viability of NK-92 cells with 0–100% SCB (left, n = 1 experiment, 3 technical replicates) and 0– 25% SCB (right, n = 1 experiment, 3 technical replicates) at 37°C; statistical analysis: one-way ANOVA with Tukey post hoc test. Bars represent mean ± SEM (ns = not significant; *p < 0.05; **p < 0.01; ****p < 0.0001).

Article Snippet: NK-92 cells (ATCC ® CRL-2407TM, American Type Culture Collection, Manassas, VA, USA) were cultured in MEM-α (Sigma-Aldrich) with 12.5% fetal calf serum (FCS; PAN-Biotech), 12.5% horse serum (PAN-Biotech), 100 U/mL penicillin plus 100 μg/mL streptomycin (Sigma-Aldrich), and 100 U/mL recombinant human Interleukin-2 (IL-2) (Proleukin S, Novartis, Basel, Switzerland).

Techniques: Flow Cytometry, Incubation

Journal: bioRxiv

Article Title: A Cellular Cytotoxicity Assay using Ready-to-Thaw Target Cells without Washing Steps

doi: 10.64898/2026.01.21.700863

Figure Lengend Snippet: Analysis of specific lysis of washed versus non-washed target cells using bead-based absolute counting or viability-based calculation across effector-to-target (E:T) ratios. A: Schematic of the analysis workflow; after flow cytometric acquisition, specific lysis was calculated using either counting beads to derive viable targets per defined volume (bead-based) or the numbers of live and dead targets (viability-based). Created in BioRender. Kaltschmidt, C. (2025) https://BioRender.com/x49u069 B: Specific lysis in assays using primary NK (pNK) cells as effectors (left: viability-based; right: bead-based; n = 5 donors/experiments, each 2–3 technical replicates). C: Specific lysis in assays using NK-92 cells as effectors (left: viability-based; right: bead-based; n = 1 experiment, 3 technical replicates). Statistical analysis: two-way ANOVA with Sidak post hoc test. Bars represent mean ± SD (*p < 0.05; ***p < 0.001; ****p < 0.0001).

Article Snippet: NK-92 cells (ATCC ® CRL-2407TM, American Type Culture Collection, Manassas, VA, USA) were cultured in MEM-α (Sigma-Aldrich) with 12.5% fetal calf serum (FCS; PAN-Biotech), 12.5% horse serum (PAN-Biotech), 100 U/mL penicillin plus 100 μg/mL streptomycin (Sigma-Aldrich), and 100 U/mL recombinant human Interleukin-2 (IL-2) (Proleukin S, Novartis, Basel, Switzerland).

Techniques: Lysis

Journal: bioRxiv

Article Title: A Cellular Cytotoxicity Assay using Ready-to-Thaw Target Cells without Washing Steps

doi: 10.64898/2026.01.21.700863

Figure Lengend Snippet: Cellular cytotoxicity assay using ready-to-thaw target cells without washing. CFSE-stained K562 targets were frozen in 40 µL aliquots of SCB with 20% FCS using isopropanol thermal buffering, thawed by direct addition of pre-warmed medium, and co-incubated with NK-92 cells for 4 h; EDTA and propidium iodide were then added for conjugate dissociation and dead-cell staining. A: Relative (left) and absolute (right) viability of target cells with-out NK-92 before cryopreservation, after thawing, and after the cytotoxicity assay (n = 1 experiment, 4–5 technical replicates: 5 before cryopreservation; 4 for both post-thaw conditions); statistical analysis: ordinary one-way ANOVA with Tukey post hoc test (both). B: Consistency of viable recovery (left) enables adjustment of pre-cryo-preservation target-cell density to achieve the desired post-thaw cell count (right) (n = 1 experiment, 4–5 technical replicates: 5 before cryopreservation; 4 after thawing); statistical analysis: unpaired t test (both). C: Specific lysis measured with NK-92 effectors by viability-based calculation (upper) and by volumetric absolute counts (lower) (n = 1 experiment, 4–5 technical replicates per E:T ratio: 4 for 0:1 and 9:1; 5 for 1:1 and 3:1). Bars represent mean ± SEM. (*p < 0.05; ****p < 0.0001).

Article Snippet: NK-92 cells (ATCC ® CRL-2407TM, American Type Culture Collection, Manassas, VA, USA) were cultured in MEM-α (Sigma-Aldrich) with 12.5% fetal calf serum (FCS; PAN-Biotech), 12.5% horse serum (PAN-Biotech), 100 U/mL penicillin plus 100 μg/mL streptomycin (Sigma-Aldrich), and 100 U/mL recombinant human Interleukin-2 (IL-2) (Proleukin S, Novartis, Basel, Switzerland).

Techniques: Cytotoxicity Assay, Staining, Incubation, Preserving, Cell Characterization, Lysis