The later stages of apoptosis are characterized by changes in nuclear morphology, including DNA fragmentation, chromatin condensation, degradation of nuclear envelope, nuclear blebbing, and DNA strand breaks. We offer a variety of reagents for analyzing nuclear changes during apoptosis; many are compatible with other reagents and procedures used to detect additional cell health and viability parameters.
Also see nuclear assays for flow cytometry
Nuclear apoptosis assays
Cells undergoing apoptosis display an increase in nuclear chromatin condensation, which is visible using NucBlue™ Live Cell Stain. Nuclear staining works for live or fixed cells and is readily combined with other detection procedures. DNA fragmentation that occurs during apoptosis produces DNA strand breaks, which can be analyzed using TUNEL (terminal deoxynucleotidyl transferase dUTP nick end-labeling) assays. TUNEL assays using Click-iT™ Plus technology can be used to study cultured cells and tissue sections, including FFPE-treated samples.
|
DNA stain to visualize chromatin condensation
DNA stains provide the fastest and most convenient route to distinguish the condensed nuclei in apoptotic cells. Nuclear staining can be performed on live or fixed cells, and we offer a choice of wavelengths for multiplexing with other cellular labels. The ReadyProbes™ formulations are stable at room temperature and provided ready to use in convenient dropper bottles. |
|
TUNEL assays for imaging and HCS
For cultured cells, the Click-iT TUNEL Alexa Fluor™ Imaging Assays are optimized for HCS or microscope imaging. The small and specific labeling moiety enables a fast and efficient experimental protocol. The assay is complete within 2 hours, and provides efficient discrimination of even high levels of apoptotic cells in a population. With a choice of fluorescent labels, the Click-iT TUNEL assay allows multiplexing with surface and intracellular biomarker detection.
|
![]() HeLa cells were treated with staurosporine to induce apoptosis and stained using the Click-iT TUNEL Alexa Fluor 594 Imaging Assay, for Microscopy & HCS and Hoechst 33342. Images were acquired using a Thermo Scientific™ ArrayScan™ VTI. |
TUNEL assays for tissue analysis
The TUNEL assay is the most widely used method to detect DNA fragmented in apoptotic cells in tissue samples. Using a small labeling moiety and a bright fluorescent dye, Click-iT Plus TUNEL assays have been demonstrated to detect apoptotic cells in several different FFPE (formalin-fixed, paraffin-embedded) tissue types. After the labeling moiety is incorporated into DNA fragments, detection is achieved through a “click” reaction using conditions mild enough to preserve the fluorescent signal from GFP or RFP and maintaining the ability to stain actin using fluorescently labeled phalloidin.
The Click-iT Plus TUNEL assay generates a bright, photostable fluorescent signal in a choice of emission colors for multiplexing fluorescent dyes or proteins to enable a variety of experimental conditions. |
|
NucBlue Live ReadyProbes Reagent
|
NucRed Live 647 ReadyProbes Reagent
|
NucBlue Fixed Cell ReadyProbes Reagent
|
|
---|---|---|---|
Readout |
Fluorescent staining of nucleic acids
|
||
Target |
Membrane-permeable dyes targeting RNA and DNA
|
Membrane impermeable dyes target RNA and DNA
|
|
Common filter set |
DAPI
|
Cy®5
|
DAPI
|
Labels |
Hoechst 33342
|
NucRed™ Live
|
DAPI
|
Ex/Em (nm) |
360/460
|
638/686
|
360/460
|
Signal-to-noise ratio |
![]() |
![]() |
![]() |
Photostability |
![]() |
![]() |
![]() |
Multiplexing |
Yes
|
Yes
|
Yes
|
Live cells |
Yes
|
Yes
|
No
|
Fixed cells |
No
|
No
|
Yes
|
Fixable |
Yes
|
No
|
No
|
Protocol | Microscopy protocol | Microscopy protocol | Microscopy protocol |
Format |
6 x dropper bottles
|
6 x dropper bottles
|
6 x dropper bottles
|
Cat. No. |
R37605
|
R37106
|
R37606
|
Click-iT TUNEL Alexa Fluor 488 Imaging Assay, for microscopy & HCS
|
Click-iT TUNEL Alexa Fluor 594 Imaging Assay, for microscopy & HCS
|
Click-iT TUNEL Alexa Fluor 647 Imaging Assay, for microscopy & HCS
|
|
---|---|---|---|
Readout |
Click-iT TUNEL Assays for DNA fragmentation provide efficient discrimination of even high levels of apoptosis in a cell population.
|
||
Conjugated dye |
Alexa Fluor 488
|
Alexa Fluor 594
|
Alexa Fluor 647
|
Standard filter set |
FITC
|
Texas Red™
|
Cy®5
|
Ex/Em (nm) |
495/519
|
590/615
|
650/670
|
Bibliography |
Citations
|
||
Fluorescence microscopy |
Yes
|
||
HCS |
Yes
|
||
HTS |
No
|
||
Multiplexing |
Yes
|
||
Live cells |
No
|
||
Fixed cells |
Mild fixation and permeabilization required
|
||
Fixable |
Yes
|
||
Format |
1 kit (1 microplate or 50 coverslips)
|
||
Cat. No. |
C10245
|
C10246
|
C10247
|
Click-iT Plus TUNEL for
in situ apoptosis detection with Alexa Fluor 488 dye
|
Click-iT Plus TUNEL for
in situ apoptosis detection with Alexa Fluor 594 dye
|
Click-iT Plus TUNEL for
in situ apoptosis detection with Alexa Fluor 647 dye
|
|
---|---|---|---|
Readout |
Click-iT Plus TUNEL Assays for DNA fragmentation provide efficient discrimination of apoptosis in tissues with multiplexing capability for organic dyes and fluorescent proteins.
|
||
Conjugated dye |
Alexa Fluor 488
|
Alexa Fluor 594
|
Alexa Fluor 647
|
Standard filter set |
FITC
|
Texas Red®
|
Cy®5
|
Ex/Em (nm) |
495/519
|
590/615
|
650/670
|
Bibliography |
Citations
|
Citations
|
Citations
|
Fluorescence microscopy |
Yes
|
||
HCS |
Yes
|
||
HTS |
No
|
||
Multiplexing |
Yes
|
||
Live cells |
No
|
||
Fixed cells |
Mild fixation and permeabilization required
|
||
Fixable |
Yes
|
||
Format |
1 kit/1 microplate or 50 coverslips
|
||
Cat. No. |
C10617
|
C10618
|
C10619
|
Click-iT TUNEL Colorimetric IHC Detection Kit
|
|
---|---|
Readout | After the incorporation of EdUTP at the site of DNA fragmentation, biotin-azide is attached to the modified nucleotide using a click reaction. The addition of enzyme and DAB substrate results in colorimetric precipitation at the positions of DNA strand breaks |
Label |
Colorimetric detection
|
Multiplexing |
Commonly used secondary tissues stains such as hematoxylin or methyl green can be used to review the cellular content surrounding the apoptotic signal.
|
Protocol | |
Sample type | Optimized for tissue sections |
Format |
1 kit/50 tests
|
Cat. No. |
C10625
|
NucBlue Live ReadyProbes Reagent
|
NucRed Live 647 ReadyProbes Reagent
|
NucBlue Fixed Cell ReadyProbes Reagent
|
|
---|---|---|---|
Readout |
Fluorescent staining of nucleic acids
|
||
Target |
Membrane-permeable dyes targeting RNA and DNA
|
Membrane impermeable dyes target RNA and DNA
|
|
Common filter set |
DAPI
|
Cy®5
|
DAPI
|
Labels |
Hoechst 33342
|
NucRed™ Live
|
DAPI
|
Ex/Em (nm) |
360/460
|
638/686
|
360/460
|
Signal-to-noise ratio |
![]() |
![]() |
![]() |
Photostability |
![]() |
![]() |
![]() |
Multiplexing |
Yes
|
Yes
|
Yes
|
Live cells |
Yes
|
Yes
|
No
|
Fixed cells |
No
|
No
|
Yes
|
Fixable |
Yes
|
No
|
No
|
Protocol | Microscopy protocol | Microscopy protocol | Microscopy protocol |
Format |
6 x dropper bottles
|
6 x dropper bottles
|
6 x dropper bottles
|
Cat. No. |
R37605
|
R37106
|
R37606
|
Click-iT TUNEL Alexa Fluor 488 Imaging Assay, for microscopy & HCS
|
Click-iT TUNEL Alexa Fluor 594 Imaging Assay, for microscopy & HCS
|
Click-iT TUNEL Alexa Fluor 647 Imaging Assay, for microscopy & HCS
|
|
---|---|---|---|
Readout |
Click-iT TUNEL Assays for DNA fragmentation provide efficient discrimination of even high levels of apoptosis in a cell population.
|
||
Conjugated dye |
Alexa Fluor 488
|
Alexa Fluor 594
|
Alexa Fluor 647
|
Standard filter set |
FITC
|
Texas Red™
|
Cy®5
|
Ex/Em (nm) |
495/519
|
590/615
|
650/670
|
Bibliography |
Citations
|
||
Fluorescence microscopy |
Yes
|
||
HCS |
Yes
|
||
HTS |
No
|
||
Multiplexing |
Yes
|
||
Live cells |
No
|
||
Fixed cells |
Mild fixation and permeabilization required
|
||
Fixable |
Yes
|
||
Format |
1 kit (1 microplate or 50 coverslips)
|
||
Cat. No. |
C10245
|
C10246
|
C10247
|
Click-iT Plus TUNEL for
in situ apoptosis detection with Alexa Fluor 488 dye
|
Click-iT Plus TUNEL for
in situ apoptosis detection with Alexa Fluor 594 dye
|
Click-iT Plus TUNEL for
in situ apoptosis detection with Alexa Fluor 647 dye
|
|
---|---|---|---|
Readout |
Click-iT Plus TUNEL Assays for DNA fragmentation provide efficient discrimination of apoptosis in tissues with multiplexing capability for organic dyes and fluorescent proteins.
|
||
Conjugated dye |
Alexa Fluor 488
|
Alexa Fluor 594
|
Alexa Fluor 647
|
Standard filter set |
FITC
|
Texas Red®
|
Cy®5
|
Ex/Em (nm) |
495/519
|
590/615
|
650/670
|
Bibliography |
Citations
|
Citations
|
Citations
|
Fluorescence microscopy |
Yes
|
||
HCS |
Yes
|
||
HTS |
No
|
||
Multiplexing |
Yes
|
||
Live cells |
No
|
||
Fixed cells |
Mild fixation and permeabilization required
|
||
Fixable |
Yes
|
||
Format |
1 kit/1 microplate or 50 coverslips
|
||
Cat. No. |
C10617
|
C10618
|
C10619
|
Click-iT TUNEL Colorimetric IHC Detection Kit
|
|
---|---|
Readout | After the incorporation of EdUTP at the site of DNA fragmentation, biotin-azide is attached to the modified nucleotide using a click reaction. The addition of enzyme and DAB substrate results in colorimetric precipitation at the positions of DNA strand breaks |
Label |
Colorimetric detection
|
Multiplexing |
Commonly used secondary tissues stains such as hematoxylin or methyl green can be used to review the cellular content surrounding the apoptotic signal.
|
Protocol | |
Sample type | Optimized for tissue sections |
Format |
1 kit/50 tests
|
Cat. No. |
C10625
|
Resources
Molecular Probes™ Handbook BioProbes Journal Articles | Related Products |