Name: Cell Counting Kit 8 (CCK-8)
Brand: AAT Bioquest
SKU: 22772
Availability: InStock

Cell Counting Kit 8 (CCK-8)

Cell Counting Kit 8 (CCK-8) is a colorimetric assay used to quantitate cell proliferation, cell viability and cytotoxicity.

Faster results with improved water solubility compared to MTT assays
Higher sensitivity compared to MTS or WST-1 assays, enabling detection of live cells at low densities
Lower cytotoxicity compared to XTT based assays, reducing the noise in the data due to assay components
Excellent stability allowing for long assays (24 - 48 hours)
Convenient workflow with a single-component, mix-and-read format
Enhanced accuracy compared to MTT assays, as it targets total dehydrogenase instead of mitochondrial dehydrogenase activity

Cell number was determined with Cell Counting Kit 8 (CCK-8). HeLa cells at 40 to 10,000 cells/well/100 µL were added in a clear bottom 96-well plate. The absorbance was measured at 460 nm using a SpectraMax reader (Molecular Devices).

Datasheet

SDS

COA

Catalog	Size	Price	Quantity
22772	1000 Tests	Price
22773	10000 Tests	Price

Overview

Product Description

CCK-8 utilizes the enzymatic activity of live cells to reduce a colorless compound into an orange dye, formazan. The amount of formazan produced, as determined by absorbance (λ460 nm), is directly proportional to the number of live cells in the sample.

Assay Principle

Metabolically active cells are known to produce dehydrogenase enzymes. Under neutral pH conditions and with the aid of an electron acceptor known as 1-methoxy phenazine methosulfate, NADPH-dependent cellular enzymes operate across the cell membrane to mediate the reduction of the colorless, cell-impermeant WST-8 tetrazolium salt. This yields an orange-colored formazan dye which is soluble in cell culture media or aqueous buffers, exhibiting strong absorption at 460 nm. This absorbance is directly proportional to the number of live cells present in the samples, serving as a reliable indicator of cell viability.

What is the difference between CCK-8 and MTT?

CCK-8 assays rely on total cell dehydrogenase activity to reduce WST-8 to an orange formazan dye, which is monitored at λ 460 nm. MTT assays rely on mitochondrial dehydrogenase activity to reduce MTT to a purple formazan dye, which is monitored at λ 562 nm. CCK-8 assays are less toxic, more sensitive and more water soluble than MTT assays.

What is the difference between CCK-8 and CellTiter-Glo?

CellTiter-Glo is a luminescence assay that relies on production of oxyluciferin from exogenous luciferin, catalyzed by luciferase in the presence of ATP from metabolically active cells. CCK-8 is a colorimetric assay that relies on production of formazan from WST-8, catalyzed by endogenous cellular dehydrogenase in the presence of NADPH from metabolically active cells.

What is the formula for CCK-8?

CCK-8 uses WST-8 as the primary reagent for detecting cell viability. The chemical name of WST-8 is 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium monosodium salt. The molecular formula for WST-8 is C20H14N6NaO11S2+. The SMILES of WST-8 is COC1=C(C=CC(=C1)N+[O-])[N+]2=NC(=NN2C3=CC=C(C=C3)N+[O-])C4=C(C=C(C=C4)S(=O)(=O)O)S(=O)(=O)[O-].[Na+].

What is the OD value of CCK-8?

CCK-8 is a colorimetric assay. The assay results can be read using an absorbance spectrophotometer. The resulting optical density (OD) value is proportional to the number of viable cells. The maximum OD value for CCK-8 occurs at 460 nm.

Is CCK-8 light sensitive?

CCK-8 should be stored so as to minimize light exposure. The recommended storage condition is < -15 °C.

Citations

View all 3 citations: Citation Explorer

Sinulariolide Suppresses Inflammation of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis and Mitigates Collagen-Induced Arthritis Symptoms in Mice

Authors:

Tsai, Sen-Wei and Cheng, Yu-Chieh and Chao, Ya-Hsuan and Yang, Deng-Ho

Journal:

Journal of Inflammation Research (2024): 8299--8311

Synthesis, structure, cytotoxicity, photodynamic reactivities and molecular simulation studies of three [RuNO (Qn)(Pro) Cl] isomeric complexes

Authors:

Liu, Chenyang and Jiao, Shuxiang and Liu, Yuhua and Wu, Tao and Xie, Leilei and Zhang, Lijuan and Zhang, Yun and Wang, Wenming and Wang, Hongfei

Journal:

Journal of Molecular Structure (2024): 140243

Simultaneous co-assembly of collagen and glycosaminoglycans to build a biomimetic extracellular matrix for bone regeneration

Authors:

Zhang, Ye and Zhou, Xinye and Liu, Qing and Shen, Minjuan and Liu, Ying and Zhang, Xu

Journal:

International Journal of Biological Macromolecules (2024): 135535

References

View all 50 references: Citation Explorer

An investigation on the changes of serum CCK-8, substance P, and 5-HT in patients with post-stroke insomnia.

Authors:

Zhang, Xiao-Hua and Zhang, Xin and Feng, Hong-Ye and Cao, Chang-Chun and Lv, Hui-Lan and Wang, Yu-Long and Ren, Li-Jie

Journal:

Technology and health care : official journal of the European Society for Engineering and Medicine (2023): 2355-2361

Correlation research of serum substance P, CCK-8, and 5-HT values with depression levels in stroke survivors.

Authors:

Zhang, X and Wang, C-B and Duan, L-H and Long, J-J and Xiao, P and Wang, Y-L and Zhang, X-H and Liu, Q-Q

Journal:

European review for medical and pharmacological sciences (2023): 1248-1254

An optimized protocol to detect protein ubiquitination and activation by ubiquitination assay in vivo and CCK-8 assay.

Authors:

Lin, Xiao-Tong and Zhang, Jie and Xie, Chuan-Ming

Journal:

STAR protocols (2023): 102199

CCK-8 enhances acid-sensing ion channel currents in rat primary sensory neurons.

Authors:

Qin, Qing-Rui and Xu, Zhong-Qing and Liu, Ting-Ting and Li, Xue-Mei and Qiu, Chun-Yu and Hu, Wang-Ping

Journal:

Neuropharmacology (2023): 109739

Inhibitory Effect of CCK-8 on Methamphetamine-Induced Apoptosis.

Authors:

Zhang, Wu-Hua and Zhang, Ming-Long and Jing, Wei-Wei and Xie, Bing and Bi, Hai-Tao and Yu, Feng and Cong, Bin and Ma, Chun-Ling and Wen, Di

Journal:

Fa yi xue za zhi (2021): 796-805

Storage, safety and handling

H-phrase	H303, H313, H333
Hazard symbol	XN
Intended use	Research Use Only (RUO)
R-phrase	R20, R21, R22
Storage	Freeze (< -15 °C); Minimize light exposure
UNSPSC	12352200

Instrument settings

Absorbance microplate reader
Absorbance	460 nm
Recommended plate	Clear bottom

Telephone
Fax
Email	sales@aatbio.com
International	See distributors
Bulk request	Inquire
Custom size	Inquire
Technical Support	Contact us
Request quotation	Request
Purchase order	Send to sales@aatbio.com
Shipping	Standard overnight for United States, inquire for international

Page updated on March 6, 2026