DNA fragmentation is the main biochemical characteristic of cell apoptosis. Chromatin DNA breaks at the junctions between nucleosomeunits, forming large DNA fragments with a length of 50~300kbp, or oligonucleotide fragments with integer multiples of 180~200bp. Creative Bioarray can provide fast, convenient, and accurate TUNEL assay services.


In apoptosis, chromosomal DNA double-strand breaks or single-strand breaks produce a large number of sticky 3'-OH ends. Derivatives formed by deoxyribonucleotides and luciferin, peroxidase, alkaline phosphatase or biotin are labeled to the 3'-end of DNA under the action of deoxyribonucleotide terminal transferase (TdT). Thus, apoptotic cells can be detected. This type of method is called terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL).

Our Services

We provide an improved TUNEL assay to help customers' research. Our services include but are not limited to:

Click-iT TUNEL Assays Service

Traditional TUNEL analysis has many limitations. In the early analysis, dUTP is usually labeled with biotin or fluorescein, and its labeled dUTP has low efficiency in incorporating DNA. It was later improved using Br-dUTP to replace biotin or fluorescein-labeled dUTP. However, Br-dUTP needs to be detected with antibodies, which requires strict reaction conditions.

Click-iT TUNEL Assays Service

Creative Bioarray uses dUTP modified with alkyne groups (EdUTP), which is smaller than Br-dUTP and is more easily incorporated into DNA ends by TdT. Through a copper-catalyzed reaction between azide and alkyne (click reaction), the alkyne group is covalently linked to the azide compound, and TUNEL detection is performed with the aid of biotin or fluorescent label on the azide. We provide three kinds of fluorescein (Alexa Fluor 640, Alexa Fluor 488, FITC) labeled TUNEL detection.

Experiment Process

Experiment process

Advantages of Improved TUNEL Assay

  • High penetration rate
  • Mild fixation and permeabilization conditions
  • Highly specific
  • Lower background interference
  • More stable covalent bonding products

Suitable for

Paraffin-embedded tissue sections, frozen tissue sections, cultured cells and cells isolated from tissues.

Customer Notice

Customers provide

  • Samples such as paraffin-embedded tissue sections, frozen tissue sections, cultured cells, cells isolated from tissues
  • The choice of test fluorescents and detection methods
  • Test purposeand requirements

We deliver

  • Experiment process
  • Instruments and reagents used
  • Photos and relevant analysis data
  • Complete experiment report

Experiment cycle

The time depends on the experiment content

Advantages of Our Services

  • Flexible solution

    Different types of samples can be tested, a variety of products and testing methods are available.

  • Professional technicians

    We have rich operating experience and superb technology.

  • Cheap price

    We provide customers with the most comprehensive services at the most favorable price, and help customers save scientific research funds reasonably.

  • Accurate test results

    With the help of Creative Bioarray, customers can obtain clear, low-noise, objective and true experimental results.

If you are interested in our services, please contact us for more detailed information.

* For scientific research only

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