How to Detect Late Apoptosis?
During the late stages of cell apoptosis, the chromosome DNA undergoes double-strand or single-strand breaks, resulting in the formation of numerous sticky 3'-OH ends. These ends can be labeled with fluorescent or enzyme-tagged dUTP under the action of Terminal deoxynucleotidyl Transferase (TdT). This allows for the detection of apoptotic cells, a method known as the TUNEL assay. Since normal or proliferating cells rarely have DNA breaks, and therefore few 3'-OH ends are formed, they are rarely stained. Currently, Arcegen offers a TUNEL Cell Apoptosis Detection Kit suitable for late apoptosis detection.
Figure 5. Principle of TUNEL Experiment
1. TUNEL Probe can Detect Different Samples including Paraffin-embedded Tissue Sections, Frozen Tissue Sections, Cultured Cells, and Cells Isolated from Tissues
TUNEL assay kits with different fluorescent colors can label different samples such as cells, cell smears, paraffin sections, etc., emitting different fluorescence signals.
Figure 6a. TUNEL-FITC Detection of Cell Samples, Source: Reference
Figure 6b. TUNEL-Alexa488 Detection of Paraffin Sections, Source: Reference
Figure 6c. TUNEL-Alexa640 Detection of Cell Smears, Source: Reference
2. Targeting Specific DNA Fragmentation in Late Apoptosis with High Selectivity and Sensitivity
At nanomolar concentration levels, the TUNEL probe selectively targets and labels the sticky 3'-OH ends of fragmented DNA in late apoptotic cells, emitting strong fluorescence signals, enabling the detection of minimal amounts of apoptotic cells.
3. Diversity in Detection
Fluorescence signals can be detected using a variety of instruments including flow cytometers, fluorescence microscopes, confocal microscopes, and enzyme-linked immunosorbent assay (ELISA) readers.
Figure 7. Measurement of TUNEL Fluorescence Signal Values by Different Instruments
4. Low Background Interference and Strong Stability
There is no background interference from other fluorescent colors, resulting in clear staining. Moreover, the performance remains stable across different batches.
5. Comparative Cost-effectiveness of Arcegen TUNEL Probe to Imported Products
Under the same specifications, the price difference between Arcegen and imported TUNEL-FITC probes is compared.
Figure 8. Price Comparison of TUNEL-FITC Products between Arcegen and T Imports (Specification: 50 T)