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Flow Cytometry Analysis of Apoptotic Markers

Analyze the effect of your compound on early and late stage apoptotic cell populations

Horizon offers FACS for the identification of early and late apoptotic cell populations using FITC-Annexin V (apoptosis) and propidium iodide (PI, viability). Annexin V binds to membrane phospholipid phosphatidylserine (PS) that in apoptotic cells is translocated from the inner to the outer leaflet of the plasma membrane exposing PS to the extracellular space. Viable cells with an intact plasma membrane exclude PI, whereas the plasma membranes of dead and damaged cells are permeable to PI.

Viable cells are Annexin V and PI negative

Early apoptotic cells are Annexin V positive and PI negative

Late apoptotic cells (or the cells that are already dead) are Annexin V and PI positive

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  • Up to 4 cell lines can be tested*
  • Up to 4 treatments*, 2 time-points (triplicate technical replicates)
  • Detection: FITC-Annexin V (apoptosis) and Propidium iodide (PI, viability)
  • Analysis: FACSverse instrument (BD Biosciences) and FlowJo software
  • Deliverables: Interim report, analyzed flow cytometry results and images, raw data

*Other combinations of cell lines and treatments are also possible – up to 16 treatment conditions analysed at 2 time points can be included in the assay

Case study: Effect of Staurosporine on Progression of Apoptosis

  • MDA-MB-231 breast cancer cells were treated with staurosporine (0, 1 mM) for 24 h.
  • Cells were harvested and stained using the Annexin V - Alexa Fluor 488 conjugate (apoptosis) and propidium iodide (Pi) Staining Solution (cell death).
  • Data were collected using a FACS-verse instrument (BD Biosciences).
  • Conclusions: Levels of both Annexin V and propidium iodide increase, indicating the presence of an early and late apoptotic cell population.


Download the complete application note about our apoptosis assays