Propidium Iodide (PI) is a nuclear staining agent that stains DNA. Propidium Iodide is an analogue of ethidine bromide that emits red fluorescence upon embedding in double-stranded DNA. Propidium Iodide cannot pass through living cell membranes, but it can pass through damaged cell membranes to stain the nucleus. Propidium Iodide has a fluorescence wavelength of 493/617 nm and a wavelength of 536/635 nm after Mosaic with DNA. Propidium Iodide is commonly used in the detection of apoptosis (apoptosis) or necrosis (necrosis), and is often used in flow cytometry analysis.

Guide (The following is our recommended solution. This solution is merely a guideline and should be modified according to your specific needs.)
1. Prepare the storage solution and working solution

1.1 Prepare the storage solution
Prepare the 1 mg/mL stock solution using DDH₂O.
1.2 Preparation of working solution
Dilute the stored solution with pre-heated serum-free cell culture medium or PBS to prepare a 20-50 μg/mL working solution of Propidium Iodide.
Note: Please adjust the concentration of the Propidium Iodide working solution according to the actual situation, and prepare it as needed.
2. Cell Staining (Suspension Cells)
2.1 Centrifuge to collect the cells, then add PBS for two washes, each for 5 minutes. The cell density is 1×10⁶ per mL.
2.2 Add 1 mL of the working solution and incubate at room temperature for 5 to 10 minutes.
2.3 400 grams. Centrifuge for 3-4 minutes. Discard the supernatant.
2.4 Add PBS to wash the cells twice, for 5 minutes each time.
2.5 After resuspending the cells in 1 mL of serum-free medium or PBS, observe them using a fluorescence microscope or a flow cytometer.
3. Cell Staining (Monolayer Cells)
3.1 Place the monolayer cells on a sterile cover slip.
3.2 Remove the cover glass from the culture medium and aspirate away the excess medium.
3.3 Add 100 μL of the dye working solution and gently shake to ensure complete coverage of the cells. Incubate for 5 to 30 minutes.
3.4 Remove the dye working solution and wash with the culture medium 2-3 times, for 5 minutes each time. Observe under a fluorescence microscope.
Note: If flow cytometry is to be used for detection, the cells should first be digested with trypsin, resuspended, and then stained.

Notes
1. Please adjust the concentration of Propidium Iodide working solution and the incubation time according to the actual situation.
2. Only the nuclei of dead cells will be stained red. 3. This product is exclusively for professional scientific research purposes only. It shall not be used for clinical diagnosis or treatment, nor for food or medicine.
3. Propidium Iodide is carcinogenic. For your safety and health, please wear a laboratory coat and use disposable gloves when operating.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year (sealed storage, away from moisture and light). When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

• [1]. Hezel M, et al. Propidium iodide staining: a new application in fluorescence microscopy for analysis of cytoarchitecture in adult and developing rodent brain. Micron. 2012 Oct;43(10):1031-8.  [Content Brief]

  [2]. Nicoletti I, et al. A rapid and simple method for measuring thymocyte apoptosis by propidium iodide staining and flow cytometry. J Immunol Methods. 1991 Jun 3;139(2):271-9.  [Content Brief]

  [3]. A rapid and simple method for measuring thymocyte apoptosis by propidium iodidestaining and flow cytometry. J Immunol Methods. 1991 Jun 3;139(2):271-9.  [Content Brief]