READIDROP™ Propidium Iodide

Propidium Iodide (PI) is a fluorescent dye that binds to DNA and RNA in a stoichiometric ratio. PI is not membrane permeable and therefore requires the compromised membranes of dead cells to bind to DNA. Upon excitation with an appropriate light source, dead cells exhibit higher fluorescence intensity than live cells, thereby enabling clear discrimination of these populations by flow cytometry. Dead cells can then be excluded from further analysis and also sorted from cell populations of interest. The spectral properties (Excitation 535 nm/Emission 617 nm) enable use in both single color and multi color flow experiments. The convenient dropper bottle format removes the manual weighing, pipetting and dilution steps required by other commonly available PI products.

This product has been reported to work in the following applications. This information is derived from testing within our laboratories, peer-reviewed publications or personal communications from the originators. Please refer to references indicated for further information. For general protocol recommendations, please visit the antibody protocols page.

Application Name	Verified	Min Dilution	Max Dilution
Flow Cytometry		1/250	1/500

Instructions For Use

Caution: Wear gloves, safety glasses/face protection, and protective clothing to avoid direct contact of ReadiDrop solutions with skin and eyes. Refer to MSDS for more information.

1. Resuspend 1 x 10⁶ cells in 500 μl flow cytometry buffer (1x phosphate buffered saline with 3% BSA). The cell concentration is now 2 x 10⁶/ml.

2. Add one to two drop of ReadiDrop Propidium Iodide to the cell suspension.

3. Vortex briefly.

4. Incubate for 1-10 min at room temperature.

Note: Adding one drop to a 500 μl cell suspension produces a final dye concentration of 1 μg/ml. This is typically sufficient to stain 1 x 10⁶ cells. If one drop is not sufficient for your cell type, adding a second drop may improve staining efficacy. When working with a larger volume of cells, scale ReadiDrop solution amount accordingly.

5. Analyze cells by flow cytometry.

- Detect PI signal in FL3 on Bio-Rad's S3e Cell Sorter. Otherwise, select the most appropriate FL channel on your particular instrument.