Many different approaches are utilized in the study of programmed cell death or apoptosis. Cell death cascades are complex and dynamic, underscoring the importance of a multi-parametric approach to assessment of apoptosis. Understanding the mechanisms of cell death and survival can represent a critical aspect of toxicological profiling and drug discovery.  Life Technologies offers a variety of products for developed for multiplex imaging-based detection of key apoptotic markers on high content screening platforms or classic fluorescence microscopy.

Our newest product for detecting apoptosis is the Click-iT® TUNEL Imaging Assays which utilize a dUTP nucleotide modified with an alkyne, a small functional group that enables the nucleotide to be more readily incorporated by TdT than other modified nucleotides. Detection is based on a click reaction between the alkyne and an azide modified dye.  Compared to other TUNEL assays, the Click-iT® TUNEL assay is able to detect a higher percentage of apoptotic cells under identical conditions. The assay is also fast and is complete within 2 hours. Furthermore, the Click-iT® TUNEL assay allows multiplexing with surface and intracellular biomarker detection.


Click-iT EdU TUNEL Schematic
Figure 1—Detection of apoptosis with the Click-iT® TUNEL imaging assay.

Product                               Cat. no.
Emission
 Color*
Ex/Em† Live‡ Fixed§ Fixable**
Click-iT® TUNEL Alexa Fluor® 488
Imaging Assay
C10245   350/461
495/519
 
 
 
Click-iT® TUNEL Alexa Fluor® 594 Imaging AssayC10246 350/461
590/615
 
 
 
 
Click-iT® TUNEL Alexa Fluor® 647 Imaging AssayC10247 350/461
650/670
 
 
 
 
Image-iT® LIVE Green Caspase-3 and -7 Detection KitI35106     350/461
488/530
535/617
 
Image-iT® LIVE Red Caspase-3 and -7 Detection KitI35102  350/461
504/523
550/595
  
Image-iT® LIVE Green Caspase-8 Detection KitI13505  350/461
488/530
535/617
 
Image-iT® LIVE Green Poly Caspases Detection KitI13504  350/461
488/530
535/617
 
Image-iT® LIVE Red Poly Caspases Detection KitI35101  350/461
504/523
550/595
 
SelectFX® Alexa Fluor® 488 Cytochrome c Apoptosis Detection KitS35115495/519
 
 
* Gray represents fluorescence emission that is beyond the limit of human vision. † Ex/Em = Fluorescence excitation and emission maxima in nm. ‡ Stains live cells. § Stains fixed cells. ** Staining pattern is fixable. NA = Not applicable.
 

Life Technologies offers LIVE/DEAD® Viability and Cytotoxicity kits, an extensive line of reagents and assays for determining cell viability on a wide variety of instrument platforms. The diversity of live cells and their environments makes it impossible to devise a single viability assay applicable to all cell types. Because viability is not easily defined in terms of a single physiological or morphological parameter, it is often desirable to combine several different measures, such as enzymatic activity, membrane permeability, and oxidation–reduction (redox) potential, when determining cell health or drug toxicity. Each assay method has inherent advantages and limitations and may introduce specific biases into the experiment; thus, different applications often call for different approaches.One of the most reliable methods for determining cell death is to use an impermeant dye that can only enter cells and become detectable if the plasma membrane is compromised or degraded.

Our latest addition to these viability kits is the HCS LIVE/DEAD® Green Kit. Validated for HCS platforms, this kit combines HCS NuclearMask™ Deep Red stain to indicate total cell numbers along with Image-iT® DEAD Green™ viability stain for discrimination of dead cells by plasma membrane integrity. Both probes bind to nucleic acids, and, because signals are retained adequately after fixation and permeabilization, this assay may be combined with antibody labeling. Hoechst 33342 is also provided in the kit as an alternate segmentation tool to maximize multiplex options.

Product                               Cat. no.
Emission Color*
Ex/Em† Live‡ Fixed§ Fixable**
Image-iT® DEAD Green™ viability stain I10291  488/515
 
 
HCS LIVE/DEAD® Green KitH10290       350/461
488/515
638/686
 
 
* Gray represents fluorecsence emission that is beyond the limit of human vision. † Ex/Em = Fluorescence excitation and emission maxima in nm. ‡ Stains live cells. § Stains fixed cells. ** Staining pattern is fixable. NA = Not applicable.