TUNEL Apoptosis Detection Kit (FITC)



When cells undergo apoptosis, they activate endonuclease enzymes that cut genomic DNA between nucleosomes. DNA ladder of 180-200 bp can be detected by electrophoresis after extraction of DNA during apoptosis.

TUNEL (TdT mediated dUTP Nick End Labeling) Cell apoptosis Assay Kit (FITC) can be used to detect the nuclear DNA breakage in tissue cells during late apoptotic stage. The principle is that FITC-12-dUTP is inserted into the 3'-hydroxyl (3'-OH) terminal of genomic DNA exposed during DNA break under the action of Terminal Deoxynucleotidyl Transferase (TdT). This can be detected by fluorescence microscopy or flow cytometry.

This kit optimizes the labeling reaction by using FITC-12-dUTP and unlabeled dNTP at the optimal ratio for nucleotide incorporation at the 3' -OH terminal, resulting in a longer "labeling tail" at the end of the same broken DNA fragment. The “labeling tail” reduces the steric hindrance of labeled groups on adjacent dNTP, increases the number of fluorescent-groups on each broken fragment, and reduces the aggregation and quenching that may be caused by adjacent fluorescent-groups, thus improving detection sensitivity and reducing non-specific reactions. 

This kit has a wide range of applications. It can be used to detect apoptosis in frozen or paraffin sections, as well as in culture adherent cells or suspension cells situation.


  • The reagents in this kit are provided in liquid form for easy use.
  • The kit can be used for a variety of purposes: flow cytometry, fluorescence microscopy for detection.
  • Under the fluorescence microscope, the color distinction is obvious.


  • This kit can be used for flow cytometry and fluorescence microscopy.
  • This kit can detect the early apoptosis of cells.
  • This kit can distinguish between late apoptotic and necrotic cells.


Application The verified application of the kit was to detect apoptotic cells by flow cytometry or immunofluorescence cytology.
Packing form Bottle


Component Name 40306ES20 (20T) 40306ES50 (50T) 40306ES60 (100T)
40306-A 5×Equilibration Buffer 750 μL 1.25 mL×2 1.25 mL×3
40306-B FITC-12-dUTP Labeling Mix 100 μL 250 μL 250 μL×2
40306-C Recombinant TdT Enzyme 20 μL 50 μL 50 μL×2
40306-D Proteinase K (2 mg/mL) 40 μL 100 μL 100 μL×2
40306-E DNase I (1 U/ μL) 5 μL 12.5 μL 25 μL
40306-F 10 × DNase I Buffer 100 μL 250 μL 500 μL

Shipping and Storage

The product is shipped with dry ice and can be stored at -15℃ ~ -25℃ for 1 year.

Citations & References:

[1] Chen J, He W, Hu X, et al. A role for ErbB signaling in the induction of reactive astrogliosis. Cell Discov. 2017;3:17044. Published 2017 Dec 5. doi:10.1038/celldisc.2017.44(IF:10.849)

[2] Pan S, Pei L, Zhang A, et al. Passion fruit-like exosome-PMA/Au-BSA@Ce6 nanovehicles for real-time fluorescence imaging and enhanced targeted photodynamic therapy with deep penetration and superior retention behavior in tumor. Biomaterials. 2020;230:119606. doi:10.1016/j.biomaterials.2019.119606(IF:10.273)

[3] Liao Y, Li H, Cao H, et al. Therapeutic silencing miR-146b-5p improves cardiac remodeling in a porcine model of myocardial infarction by modulating the wound reparative phenotype. Protein Cell. 2021;12(3):194-212. doi:10.1007/s13238-020-00750-6(IF:10.164)

[4] Li J, Kong D, Wang Q, et al. Niacin ameliorates ulcerative colitis via prostaglandin D<sub>2</sub>-mediated D prostanoid receptor 1 activation [published correction appears in EMBO Mol Med. 2020 Dec 7;12(12):e13487]. EMBO Mol Med. 2017;9(5):571-588. doi:10.15252/emmm.201606987(IF:9.249)

[5] Li X, Gui R, Li J, et al. Novel Multifunctional Silver Nanocomposite Serves as a Resistance-Reversal Agent to Synergistically Combat Carbapenem-Resistant Acinetobacter baumannii. ACS Appl Mater Interfaces. 2021;13(26):30434-30457. doi:10.1021/acsami.1c10309(IF:9.229)

[6] Fu H, Zhang W, Yuan Q, et al. PAK1 Promotes the Proliferation and Inhibits Apoptosis of Human Spermatogonial Stem Cells via PDK1/KDR/ZNF367 and ERK1/2 and AKT Pathways. Mol Ther Nucleic Acids. 2018;12:769-786. doi:10.1016/j.omtn.2018.06.006(IF:8.886)

[7] Aung LHH, Chen X, Cueva Jumbo JC, et al. Cardiomyocyte mitochondrial dynamic-related lncRNA 1 (CMDL-1) may serve as a potential therapeutic target in doxorubicin cardiotoxicity. Mol Ther Nucleic Acids. 2021;25:638-651. Published 2021 Aug 19. doi:10.1016/j.omtn.2021.08.006(IF:8.886)

[8] Qian Y, Wang Y, Jia F, et al. Tumor-microenvironment controlled nanomicelles with AIE property for boosting cancer therapy and apoptosis monitoring. Biomaterials. 2019;188:96-106. doi:10.1016/j.biomaterials.2018.10.003(IF:8.806)

[9] Liu Q, Qian Y, Li P, et al. <sup>131</sup>I-Labeled Copper Sulfide-Loaded Microspheres to Treat Hepatic Tumors via Hepatic Artery Embolization. Theranostics. 2018;8(3):785-799. Published 2018 Jan 1. doi:10.7150/thno.21491(IF:8.537)

[10] Wang H, Yuan Q, Niu M, et al. Transcriptional regulation of P63 on the apoptosis of male germ cells and three stages of spermatogenesis in mice. Cell Death Dis. 2018;9(2):76. Published 2018 Jan 23. doi:10.1038/s41419-017-0046-z(IF:8.469)

[11] Huang J, Yu W, He Q, et al. Autophagy facilitates age-related cell apoptosis-a new insight from senile cataract. Cell Death Dis. 2022;13(1):37. Published 2022 Jan 10. doi:10.1038/s41419-021-04489-8(IF:8.469)

[12] Zhou M, Liu X, Qiukai E, et al. Long non-coding RNA Xist regulates oocyte loss via suppressing miR-23b-3p/miR-29a-3p maturation and upregulating STX17 in perinatal mouse ovaries. Cell Death Dis. 2021;12(6):540. Published 2021 May 25. doi:10.1038/s41419-021-03831-4(IF:8.469)

[13] Wang YJ, Liu MG, Wang JH, et al. Restoration of Cingulate Long-Term Depression by Enhancing Non-apoptotic Caspase 3 Alleviates Peripheral Pain Hypersensitivity. Cell Rep. 2020;33(6):108369. doi:10.1016/j.celrep.2020.108369(IF:8.109)

[14] Wan Y, Feng B, You Y, et al. Microglial Displacement of GABAergic Synapses Is a Protective Event during Complex Febrile Seizures. Cell Rep. 2020;33(5):108346. doi:10.1016/j.celrep.2020.108346(IF:8.109)

[15] Yang X, Zhao X, Zhu Y, et al. FKBP3 Induces Human Immunodeficiency Virus Type 1 Latency by Recruiting Histone Deacetylase 1/2 to the Viral Long Terminal Repeat. mBio. 2021;12(4):e0079521. doi:10.1128/mBio.00795-21(IF:7.867)

[16] Sun Z, Huang J, Su L, et al. Arf6-mediated macropinocytosis-enhanced suicide gene therapy of C16TAB-condensed Tat/pDNA nanoparticles in ovarian cancer. Nanoscale. 2021;13(34):14538-14551. Published 2021 Sep 2. doi:10.1039/d1nr03974a(IF:7.790)

[17] Fan S, Zhang Y, Tan H, et al. Manganese/iron-based nanoprobes for photodynamic/chemotherapy combination therapy of tumor guided by multimodal imaging. Nanoscale. 2021;13(10):5383-5399. doi:10.1039/d0nr08831e(IF:7.790)

[18] Tang K, Qin W, Wei R, et al. Ginsenoside Rd ameliorates high glucose-induced retinal endothelial injury through AMPK-STRT1 interdependence. Pharmacol Res. 2022;179:106123. doi:10.1016/j.phrs.2022.106123(IF:7.658)

[19] Yang X, Wang Y, Lu P, et al. PEBP1 suppresses HIV transcription and induces latency by inactivating MAPK/NF-κB signaling. EMBO Rep. 2020;21(11):e49305. doi:10.15252/embr.201949305(IF:7.497)

[20] Liu B, Qiao G, Han Y, et al. Targeted theranostics of lung cancer: PD-L1-guided delivery of gold nanoprisms with chlorin e6 for enhanced imaging and photothermal/photodynamic therapy. Acta Biomater. 2020;117:361-373. doi:10.1016/j.actbio.2020.09.040(IF:7.242)

[21] Liu Y , Zhi X , Hou W , et al. Gd<sup>3+</sup>-Ion-induced carbon-dots self-assembly aggregates loaded with a photosensitizer for enhanced fluorescence/MRI dual imaging and antitumor therapy. Nanoscale. 2018;10(40):19052-19063. doi:10.1039/c8nr05886e(IF:7.233)

[22] Wu D, Hu Q, Tan B, Rose P, Zhu D, Zhu YZ. Amelioration of mitochondrial dysfunction in heart failure through S-sulfhydration of Ca<sup>2+</sup>/calmodulin-dependent protein kinase II. Redox Biol. 2018;19:250-262. doi:10.1016/j.redox.2018.08.008(IF:7.126)

[23] Zhang C, Chen H, He Q, et al. Fibrinogen/AKT/Microfilament Axis Promotes Colitis by Enhancing Vascular Permeability. Cell Mol Gastroenterol Hepatol. 2021;11(3):683-696. doi:10.1016/j.jcmgh.2020.10.007(IF:7.076)

[24] Zeng M, He Y, Gao X, et al. Characteristics and functions of glyceraldehyde 3-phosphate dehydrogenase S-nitrosylation during controlled aging of elm and Arabidopsis seeds. J Exp Bot. 2021;72(20):7020-7034. doi:10.1093/jxb/erab322(IF:6.992)

[25] Cao W , Liu B , Xia F , et al. MnO<sub>2</sub>@Ce6-loaded mesenchymal stem cells as an "oxygen-laden guided-missile" for the enhanced photodynamic therapy on lung cancer. Nanoscale. 2020;12(5):3090-3102. doi:10.1039/c9nr07947e(IF:6.970)

[26] Chen H, Guan B, Chen X, et al. Baicalin Attenuates Blood-Brain Barrier Disruption and Hemorrhagic Transformation and Improves Neurological Outcome in Ischemic Stroke Rats with Delayed t-PA Treatment: Involvement of ONOO<sup>-</sup>-MMP-9 Pathway. Transl Stroke Res. 2018;9(5):515-529. doi:10.1007/s12975-017-0598-3(IF:6.829)

[27] Liu Y, Yang Y, Suo Y, et al. Inducible caspase-9 suicide gene under control of endogenous oct4 to safeguard mouse and human pluripotent stem cell therapy. Mol Ther Methods Clin Dev. 2022;24:332-341. Published 2022 Feb 1. doi:10.1016/j.omtm.2022.01.014(IF:6.698)

[28] Zhang P, Han X, Zhang X, Zhu X. Lactobacillus acidophilus ATCC 4356 Alleviates Renal Ischemia-Reperfusion Injury Through Antioxidant Stress and Anti-inflammatory Responses and Improves Intestinal Microbial Distribution. Front Nutr. 2021;8:667695. Published 2021 May 11. doi:10.3389/fnut.2021.667695(IF:6.576)

[29] Hu Z, Zhang H, Yi B, et al. VDR activation attenuate cisplatin induced AKI by inhibiting ferroptosis. Cell Death Dis. 2020;11(1):73. Published 2020 Jan 29. doi:10.1038/s41419-020-2256-z(IF:6.304)

[30] Liu J, Liu B, Yuan P, et al. Role of PKA/CREB/BDNF signaling in PM2.5-induced neurodevelopmental damage to the hippocampal neurons of rats. Ecotoxicol Environ Saf. 2021;214:112005. doi:10.1016/j.ecoenv.2021.112005(IF:6.291)

[31] Liu H, Zhou W, Guo L, et al. Quercetin protects against palmitate-induced pancreatic β-cell apoptosis by restoring lysosomal function and autophagic flux [published online ahead of print, 2022 May 25]. J Nutr Biochem. 2022;107:109060. doi:10.1016/j.jnutbio.2022.109060(IF:6.048)

[32] Xie L, Huang W, Fang Z, et al. CircERCC2 ameliorated intervertebral disc degeneration by regulating mitophagy and apoptosis through miR-182-5p/SIRT1 axis. Cell Death Dis. 2019;10(10):751. Published 2019 Oct 3. doi:10.1038/s41419-019-1978-2(IF:5.959)

[33] Zhang C, He A, Liu S, et al. Inhibition of HtrA2 alleviated dextran sulfate sodium (DSS)-induced colitis by preventing necroptosis of intestinal epithelial cells. Cell Death Dis. 2019;10(5):344. Published 2019 Apr 24. doi:10.1038/s41419-019-1580-7(IF:5.959)

[34] Hu Y, Qian Y, Wei J, et al. The Disulfiram/Copper Complex Induces Autophagic Cell Death in Colorectal Cancer by Targeting ULK1. Front Pharmacol. 2021;12:752825. Published 2021 Nov 23. doi:10.3389/fphar.2021.752825(IF:5.811)

[35] Cen K, Chen M, He M, et al. Sporoderm-Broken Spores of Ganoderma lucidum Sensitizes Ovarian Cancer to Cisplatin by ROS/ERK Signaling and Attenuates Chemotherapy-Related Toxicity. Front Pharmacol. 2022;13:826716. Published 2022 Feb 21. doi:10.3389/fphar.2022.826716(IF:5.811)

[36] Mao Y, Tu R, Huang Y, et al. The exocyst functions in niche cells to promote germline stem cell differentiation by directly controlling EGFR membrane trafficking. Development. 2019;146(13):dev174615. Published 2019 Jun 28. doi:10.1242/dev.174615(IF:5.763)

[37] Zhou F, Yuan Q, Zhang W, et al. MiR-663a Stimulates Proliferation and Suppresses Early Apoptosis of Human Spermatogonial Stem Cells by Targeting NFIX and Regulating Cell Cycle. Mol Ther Nucleic Acids. 2018;12:319-336. doi:10.1016/j.omtn.2018.05.015(IF:5.660)

[38] Yang C, Yao C, Tian R, et al. miR-202-3p Regulates Sertoli Cell Proliferation, Synthesis Function, and Apoptosis by Targeting LRP6 and Cyclin D1 of Wnt/β-Catenin Signaling. Mol Ther Nucleic Acids. 2019;14:1-19. doi:10.1016/j.omtn.2018.10.012(IF:5.660)

[39] Li F, Miao L, Xue T, et al. Inhibiting PAD2 enhances the anti-tumor effect of docetaxel in tamoxifen-resistant breast cancer cells. J Exp Clin Cancer Res. 2019;38(1):414. Published 2019 Oct 10. doi:10.1186/s13046-019-1404-8(IF:5.646)

[40] Xing J, Wang M, Hong J, et al. TRPM7 channel inhibition exacerbates pulmonary arterial hypertension through MEK/ERK pathway. Aging (Albany NY). 2019;11(12):4050-4065. doi:10.18632/aging.102036(IF:5.515)

[41] Liu G, Liu Q, Shen Y, et al. Early treatment with Resolvin E1 facilitates myocardial recovery from ischaemia in mice. Br J Pharmacol. 2018;175(8):1205-1216. doi:10.1111/bph.14041(IF:5.491)

[42] Wang Z, Wang Q, Xu G, et al. The long noncoding RNA CRAL reverses cisplatin resistance via the miR-505/CYLD/AKT axis in human gastric cancer cells. RNA Biol. 2020;17(11):1576-1589. doi:10.1080/15476286.2019.1709296(IF:5.350)

[43] Yang K, Wei M, Yang Z, et al. Activation of dopamine receptor D1 inhibits glioblastoma tumorigenicity by regulating autophagic activity. Cell Oncol (Dordr). 2020;43(6):1175-1190. doi:10.1007/s13402-020-00550-4(IF:5.304)

[44] Zhang L, Yao X, Ma M, et al. Protective Effect of l-Theanine against DSS-Induced Colitis by Regulating the Lipid Metabolism and Reducing Inflammation via the NF-κB Signaling Pathway. J Agric Food Chem. 2021;69(47):14192-14203. doi:10.1021/acs.jafc.1c05839(IF:5.279)

[45] Zhang C, Luo Y, He Q, Liu S, He A, Yan J. A pan-RAF inhibitor LY3009120 inhibits necroptosis by preventing phosphorylation of RIPK1 and alleviates dextran sulfate sodium-induced colitis. Clin Sci (Lond). 2019;133(8):919-932. Published 2019 Apr 16. doi:10.1042/CS20181081(IF:5.237)

[46] Ding X, Wang S, Wang Y, et al. Neonatal Heart Responds to Pressure Overload With Differential Alterations in Various Cardiomyocyte Maturation Programs That Accommodate Simultaneous Hypertrophy and Hyperplasia. Front Cell Dev Biol. 2020;8:596960. Published 2020 Nov 19. doi:10.3389/fcell.2020.596960(IF:5.186)

[47] Gu L, Ren F, Fang X, Yuan L, Liu G, Wang S. Exosomal MicroRNA-181a Derived From Mesenchymal Stem Cells Improves Gut Microbiota Composition, Barrier Function, and Inflammatory Status in an Experimental Colitis Model. Front Med (Lausanne). 2021;8:660614. Published 2021 Jun 24. doi:10.3389/fmed.2021.660614(IF:5.093)

[48] Jiang C, Yang W, Wang C, et al. Methylene Blue-Mediated Photodynamic Therapy Induces Macrophage Apoptosis via ROS and Reduces Bone Resorption in Periodontitis. Oxid Med Cell Longev. 2019;2019:1529520. Published 2019 Aug 14. doi:10.1155/2019/1529520(IF:4.868)

[49] Li Y, Wu Y, Jiang K, et al. Mangiferin Prevents TBHP-Induced Apoptosis and ECM Degradation in Mouse Osteoarthritic Chondrocytes via Restoring Autophagy and Ameliorates Murine Osteoarthritis. Oxid Med Cell Longev. 2019;2019:8783197. Published 2019 Oct 15. doi:10.1155/2019/8783197(IF:4.868)

[50] Fan J, Chen M, Wang X, et al. Targeting Smox Is Neuroprotective and Ameliorates Brain Inflammation in Cerebral Ischemia/Reperfusion Rats. Toxicol Sci. 2019;168(2):381-393. doi:10.1093/toxsci/kfy300(IF:4.849)

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