Detection of cell-surface phosphatidylserine using the fluorogenic probe P-IID

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Phosphatidylserine (PS) externalization is a key hallmark of apoptosis.
• Current methods for PS detection, like Annexin-V, have limitations.
• A need exists for more sensitive and efficient PS detection probes.

Purpose of the Study:

• To provide a detailed protocol for using the fluorogenic probe P-IID for detecting externalized PS.
• To enable real-time imaging of apoptosis and quantitative analysis of cell death.
• To highlight the advantages of P-IID over existing PS detection methods.

Main Methods:

• Confocal microscopy for qualitative detection of externalized PS in apoptotic cells.
• Flow cytometry for quantitative analysis of cell death using P-IID and propidium iodide.
• Real-time imaging of apoptosis following drug treatment.

Main Results:

• P-IID enables "turn-on" fluorescence detection of externalized PS.
• The probe exhibits rapid binding kinetics and can be used at low temperatures (4°C).
• P-IID can be used without washing and in the absence of Ca2+ ions, simplifying protocols.

Conclusions:

• P-IID is a superior fluorogenic probe for detecting cell-surface phosphatidylserine.
• It offers significant advantages over Annexin-V conjugates for apoptosis detection.
• The detailed protocols facilitate its use in both qualitative and quantitative cell death assays.