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Updated: Jul 4, 2026
Flow Cytometric Analysis of Apoptotic Biomarkers in Actinomycin D-Treated SiHa Cervical Cancer Cells
Published on: August 26, 2021
Quantitative image based apoptotic index measurement using multispectral imaging flow cytometry: a comparison with
Shannon Henery1, Thaddeus George, Brian Hall
1Amnis Corporation, 2505 3rd Ave Suite 210, Seattle, WA 98121, USA. shenery@amnis.com
Abstract:
Morphological characterization by microscopy remains the gold standard for accurately identifying apoptotic cells using characteristics such as nuclear condensation, nuclear fragmentation, and membrane blebbing. However, quantitative measurement of apoptotic morphology using microscopy can be time consuming and can lack objectivity and reproducibility, making it difficult to identify subtle changes in large populations. Thus the apoptotic index of a sample is commonly measured by flow cytometry using a variety of fluorescence intensity based (photometric) assays which target hallmarks of apoptosis with secondary markers such as the TUNEL (Terminal Deoxynucleotide Transferase dUTP Nick End Labeling) assay for detection of DNA fragmentation, the Annexin V assay for surface phosphatidylserine (PS) exposure, and fluorogenic caspase substrates to detect caspase activation. Here a novel method is presented for accurate quantitation of apoptosis based on nuclear condensation, nuclear fragmentation, and membrane blebbing using automated image analysis on large numbers of images collected in flow by the ImageStream multispectral imaging cytometer. Additionally the measurement of nuclear fragmentation correlates with the secondary methods of detection of apoptosis over time, indicating that it is also an early marker for apoptosis. False-positive and false-negative events associated with each photometric flow cytometry based method are quantitated and can be automatically removed/included where appropriate. Acquisition of multi-spectral imagery on large numbers of cells couples the quantitative advantage of flow cytometry with the accuracy of morphology-based algorithms allowing more complete and robust analysis of apoptosis.
Insights
This study presents a novel method for accurately quantifying apoptosis by analyzing cell morphology using automated image analysis. This approach combines the speed of flow cytometry with the precision of microscopy for robust apoptosis detection.
Area of Science:
- Cell Biology
- Apoptosis Research
- Quantitative Imaging
Background:
- Microscopy is the gold standard for identifying apoptotic cells by morphology but is time-consuming and subjective.
- Current flow cytometry assays (e.g., TUNEL, Annexin V) use indirect markers and can yield false positives/negatives.
- Accurate and objective quantification of apoptosis is crucial for understanding cellular processes and disease.
Purpose of the Study:
- To develop and validate a novel method for accurate, quantitative measurement of apoptosis based on cell morphology.
- To leverage automated image analysis on multispectral imaging flow cytometry data.
- To compare morphological apoptosis markers with established flow cytometry assays.
Main Methods:
- Utilized the ImageStream multispectral imaging cytometer to collect images of cells in flow.
- Applied automated image analysis algorithms to quantify morphological features of apoptosis (nuclear condensation, fragmentation, membrane blebbing).
- Correlated morphological measurements with traditional flow cytometry assays (TUNEL, Annexin V, caspase substrates).
Main Results:
- Automated image analysis accurately quantifies apoptosis based on nuclear condensation, fragmentation, and membrane blebbing.
- Nuclear fragmentation was identified as an early marker of apoptosis, correlating with secondary detection methods.
- Quantified and enabled automated removal/inclusion of false-positive and false-negative events from photometric assays.
Conclusions:
- Multispectral imaging flow cytometry combined with automated image analysis provides a robust method for apoptosis quantification.
- This approach integrates the quantitative power of flow cytometry with the morphological accuracy of microscopy.
- The method offers a more complete and objective analysis of apoptosis compared to conventional techniques.
