Apoptosis is a mechanism of programmed cell death that is essential to normal cell turnover. Many diseases are attributable to deficient apoptosis where excessive or insufficient cell death occur. Prior to the occurence of characteristic changes in cell morphology that include cell rounding, plasma membrane blebbing and nuclear condensation, pro-apoptotic signaling pathways are triggered by cell stress. Activation of caspase proteases leading to mitochondrial alteration result in a well-orchestrated cascade of events offering a series of markers to identify various stages of apoptosis. Scientists can detect changes in mitochondrial potential associated with apoptosis with reagents such as DePsipher™; early membrane events with labeled Annexin V; DNA fragmentation with specialty TUNEL kits for fixed tissues and cells using microscopy, flow cytometry or microplate format; as well as identify specific key proteins with our line of antibodies.
For over 20 years the research community has relied on Trevigen to supply the highest quality kits for apoptosis detection under its brand name TACS® (Trevigen Apoptotic Cell System) as well as antibodies and reagents used to investigate the apoptotic state of cells and assess cell viability and proliferation.
Antibodies (5)Explore All
Trevigen’s apoptosis antibodies can be used to detect pro- or anti- apoptotic markers (see below and our PAR/PARP Antibody page). In addition, Trevigen offers detection of specific types of DNA damage such as double-strand DNA breaks (H2AX) or modification of nucleotides due to oxidative damage (8-oxo dG and BPDE). We recommend using our Anti-G3PDH (Glyceraldehyde-3-phosphate dehydrogenase) antibody as a reference in Western Blots.
Apoptosis Inducers (2)
Apoptosis inducers are chemicals or cancer fighting drugs that can be used in cellular or animal models to trigger the onset of apoptosis. The intrinsic pathway occurs in response to internal events or non-receptor-mediated stimuli, producing intracellular signals that act directly on targets within the cell and are mitochondrial-initiated events. The extrinsic pathway requires external factors often originating from the immune system that will trigger apoptosis with the involvement of transmembrane receptor such as the tumor necrosis factor (TNF) receptor superfamily. The intrinsic and the extrinsic signaling pathways converge in a single pathway called terminal, or execution pathway where cascades of proteolytic cleavage of key proteins and enzymes, including caspase 3 and poly(ADP-ribose) polymerase (PARP) result in phosphatidyl-serine (PS) exposure, DNA fragmentation and ultimately cell death under the execution pathway. Trevigen offers etoposide and staurosporine as a complement to our apoptosis line of products.
TUNEL Based Kits (23)Explore All
DNA fragmentation occurs as one of the final stages of programmed cell death and has long been considered a hallmark of apoptosis as well as one of the defining biochemical events of the pathway. DNA fragmentation can be detected in situ within the nuclei of fixed cells and tissues where the integrity of the DNA and the free 3’ hydroxyl groups at the sites of cleavage have been preserved by fixation. The DNA provides a target for terminal deoxynucleotidyl transferase (TdT), which can sequentially add nucleotides to the 3’ end at the break. The addition of a nucleotide tagged with biotin (biotin-dNTP) or BrdU in the reaction mix then allows indirect visualization of any DNA labeling by TdT. Trevigen has developed a series of TUNEL-based assay kits for the in situ detection of apoptosis with colorimetric and fluorometric options. The biotin-dNTP based TACS® kits and BrdU based TACS•XL® and DermaTACS™ are tailored for the detection of DNA fragmentation associated with apoptosis in a variety of cell and tissue types and for analysis by different formats that include microscopy, flow cytometry, and 96 well plates.
Annexin V Assays (6)Explore All
The coupling of annexin to fluorescein (Annexin V-FITC), or biotin (Annexin V-Biotin), generates a direct, rapid, and simple method for the detection of apoptosis on unfixed cells by microscopy or flow cytometry. Some of the earliest apoptotic changes occur at the cell surface. One of the better understood cell surface modifications is exposure of phosphatidylserine (PS). Normally, PS is confined to the inner layer of the lipid bilayer. This asymmetric distribution is maintained in normal cells by the action of specific proteins. After induction of apoptosis under the influence of translocases, the PS is flipped from the inner to the outer bilayer, rendering the molecule available for detection. Annexin V is a blood clotting factor that exhibits a high calcium-dependent specificity for PS binding.
Mitochondrial Assays (4)Explore All
Although organelles remain grossly normal during the earlier stages of apoptosis, research has revealed a pivotal role for mitochondria in the apoptotic cascade. The energy generated during cellular respiration accumulates in the mitochondrial transmembrane space as an electron gradient called the mitochondrial membrane potential or Δψm. This electrochemical gradient is often disturbed during apoptosis and can be detected using cationic dyes such as DePsipher™ (5,5’6,6’- tetrachloro-1,1’,3,3’-tetraethylbenz-imidazolylcarbocyanine iodide). DePsipher™ readily enters cells and accumulates as a multimeric aggregate within healthy mitochondria, and under UV light, this multimeric form emits red light. In apoptotic cells, the mitochondrial membrane potential collapses and the dye returns to a monomeric form. The monomeric molecule emits green fluorescence under UV light. DePsipher™ provides a rapid fluorescence-based assay for the apoptosis-associated loss of mitochondrial potential.
Cell Proliferation (9)Explore All
Measurement of cell proliferation is necessary for testing the effects of pharmacological agents or growth factors, assessing cytotoxicity or investigating circumstances of cell activation. In a cell proliferation assay, the increase in number of cells or change in the proportion of cells that is dividing is assessed. Trevigen® offers a Calcein-AM based kit to determine cell viability as well as the tetrazolium salts MTT and XTT metabolic cell proliferation assay kits.
Apoptosis Assay Reagents (31)
Trevigen® offers a wide range of supplemental reagents to support its TACS® apoptosis line of products. They include microscopy products such as coverslips, mounting media as well as stand-alone products for kit-based application development including controls, permeabilization reagents, counterstains and detection reagents such as streptavidin conjugates and peroxidase substrates.
- Apoptosis Grade PBS Buffer and Water
- Detection Reagents
- Mounting Media
- Permeabilization Reagents for in situ Apoptosis Detection
- Hydrophobic Coverslips
- TdT Reagents