In Situ Cell Death Detection Kit, Fluorescein


sufficient for ≤50 tests

Quality Level



shipped in

dry ice

storage temp.


General description

Kit for the detection and quantification of apoptosis at the single-cell level, based on labeling of DNA strand breaks (TUNEL technology); analysis by fluorescence microscopy or flow cytometry.
Widely used methods to determine apoptosis include the analysis of the genomic DNA by agarose-gel electrophoresis and DNA fragmentation assays based on 3H-thymidine and, alternatively, 5-Bromo-2′-deoxy-uridine. The methods involve the separation of fragmented, low molecular weight DNA from unfragmented, high molecular weight DNA in a given cell population. Thus, these methods do not provide information about the fate of an individual cell in a given cell population, or particularly, in tissue sections. Alternatively, individual apoptotic cells may be microscopically recognized because of the characteristic appearance of nuclear chromatin condensation and fragmentation, but this method is subjective and limited to a relatively narrow time window when the morphological changes are at a maximum.
The hallmark of apoptosis is DNA degradation, which in early stages, is selective to the internucleosomal DNA linker regions. The DNA cleavage may yield double-stranded and single-stranded DNA breaks (nicks). Both types of breaks can be detected by labeling the free 3′-OH termini with modified nucleotides (e.g., biotin-dUTP, DIG-dUTP, fluorescein-dUTP) in an enzymatic reaction. The enzyme terminal deoxynucleotidyl transferase (TdT) catalyzes the template-independent polymerization of deoxyribonucleotides to the 3′-end of single- and double-stranded DNA. This method has also been termed TUNEL (TdT-mediated dUTP-X nick end labeling). Alternatively, free 3′-OH groups may be labeled using DNA polymerases by the template-dependent mechanism called nick translation. However, the TUNEL method is considered to be more sensitive and faster.


The TUNEL reaction preferentially labels DNA strand breaks generated during apoptosis. This allows discrimination of apoptosis from necrosis and from primary DNA strand breaks induced by cytostatic drugs or irradiation.


The In Situ Cell Death Detection Kit, Fluorescein,  is a precise, fast, and simple nonradioactive technique to detect and quantify apoptotic cell death at the single-cell level by fluorescence microscopy and quantitative detection by flow cytometry in cells and tissues. Thus, the In Situ Cell Death Detection Kit can be used in many different assay systems.
Examples are:
  • Detection of individual apoptotic cells in frozen and formalin-fixed tissue sections in basic research
  • Determination of sensitivity of malignant cells to drug-induced apoptosis in cancer research
  • Typing of cells undergoing cell death in heterogeneous populations by double staining procedures

Features and Benefits

  • Sensitive: The direct labeling procedure using fluorescein-dUTP reduces background labeling
  • Fast: The use of fluorescein-dUTP allows analysis of the samples directly after the TUNEL reaction
  • Convenient: No secondary detection system required
  • Accurate: Identification of apoptosis at a molecular level (DNA-strand breaks) and identification of cells at the very early stages of apoptosis


1 kit containing 2 components.

Preparation Note

Working solution: Add total volume (50 μl) of Enzyme Solution to the remaining 450 μl Label Solution to obtain 500 μl TUNEL reaction mixture.
Mix well to equilibrate components.

Other Notes

For life science research only. Not for use in diagnostic procedures.

Kit Components Only

Product No.

  • Enzyme Solution (TdT)

  • Label Solution (fluorescein-dUTP)


Health hazardEnvironment

Signal Word


Hazard Statements


UN 1556 6.1 / PGIII

WGK Germany


Flash Point(F)

does not flash

Flash Point(C)

does not flash

Zengxia Li et al.
Biologics : targets & therapy, 1(4), 455-463 (2007-12-01)
Medullary thyroid carcinoma (MTC), a neuroendocrine tumor arising from the thyroid gland, is known to be poorly responsive to conventional chemotherapy. The root of Stemona tuberosa Lour, also called Bai Bu, is a commonly used traditional Chinese anti-tussive medicine. The...
Laura Perin et al.
PloS one, 5(2), e9357-e9357 (2010-03-03)
Acute Tubular Necrosis (ATN) causes severe damage to the kidney epithelial tubular cells and is often associated with severe renal dysfunction. Stem-cell based therapies may provide alternative approaches to treating of ATN. We have previously shown that clonal c-kit(pos) stem...
Shih Lung Cheng et al.
Respiratory research, 10, 115-115 (2009-11-26)
Although both animal and human studies suggested the association between placenta growth factor (PlGF) and chronic obstructive pulmonary disease (COPD), especially lung emphysema, the role of PlGF in the pathogenesis of emphysema remains to be clarified. This study hypothesizes that...
Raphaël Roduit et al.
Apoptosis : an international journal on programmed cell death, 13(3), 343-353 (2008-02-07)
The retinal pigment epithelium (RPE) is constantly exposed to external injuries which lead to degeneration, dysfunction or loss of RPE cells. The balance between RPE cells death and proliferation may be responsible for several diseases of the underlying retina, including...
A García-Peiró et al.
International journal of andrology, 34(6 Pt 2), e546-e553 (2011-05-04)
This investigation was conducted to assess the baseline level of sperm DNA fragmentation (SDF) in a cohort of patients presenting chromosomal rearrangements (nine reciprocal translocations and two inversions). In a separate experiment, a dynamic analysis to calculate the rate of...
Cellular apoptosis assays to detect programmed cell death using Annexin V, Caspase and TUNEL DNA fragmentation assays.
Read More

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon


Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.