PKH 26

• CAT Number: I044987
• CAS Number: 154214-55-8
• Molecular Formula: C59H97IN2
• Molecular Weight: 961.32
• Purity: ≥95%
• Synonyms: 2-[(E,3E)-3-(3,3-dimethyl-1-tetradecylindol-2-ylidene)prop-1-enyl]-1-docosyl-3,3-dimethylindol-1-ium;iodide
• InChI: InChI=1S/C59H97N2.HI/c1-7-9-11-13-15-17-19-21-22-23-24-25-26-27-28-30-32-34-36-42-51-61-55-47-40-38-45-53(55)59(5,6)57(61)49-43-48-56-58(3,4)52-44-37-39-46-54(52)60(56)50-41-35-33-31-29-20-18-16-14-12-10-8-2;/h37-40,43-49H,7-36,41-42,50-51H2,1-6H3;1H/q+1;/p-1
• InChIKey: XOOOYQALQHJRCY-UHFFFAOYSA-M
• SMILES: CCCCCCCCCCCCCCCCCCCCCC[N+]1=C(C(C2=CC=CC=C21)(C)C)C=CC=C3C(C4=CC=CC=C4N3CCCCCCCCCCCCCC)(C)C.[I-]

PKH 26 is a red fluorescent dye, PKH 26 can stably bind to the lipid region of cell membrane and emit red fluorescence (Ex/Em=551/567 nm), which is mainly used for in vitro cell labeling, in vitro cell proliferation studies and in vivo and in vitro cell tracing studies[1].
General Protocol
1.Preparation of PKH 26 working solution
1.1Preparation of the stock solution
Dissolve 1 mg PKH 26 in 1 mL DMSO to obtain 1 mM of stock solution.
Note: It is recommended to store the stock solution at -20°C and -80°C away from light and avoid repetitive freeze-thaw cycles.
1.2Preparation of PKH 26 working solution
Dilute the stock solution in serum-free cell culture medium or PBS dilute at 1:50 or 1:100 to obtain 5-10 μM of working solution.
Note: Please adjust the concentration of PKH 26 working solution according to the actual situation.
2.Cell staining
2.1 Suspension cells（6-well plate）
a.Centrifuge at 1000 g at 4°C for 3-5 minutes and then discard the supernatant. Wash twice with PBS, 5 minutes each time.The cell density is 1×106/mL.
b.Add 1 mL of working solution, and then incubate at room temperature for 10-45 minutes.
c.Centrifuge at 400 g at 4°C for 3-4 minutes and then discard the supernatant.
d.Wash twice with PBS, 5 minutes each time.
e.Resuspend cells with serum-free cell culture medium or PBS. Observation by fluorescence microscopy or flow cytometry.
2.2 Adherent cells
a. Culture adherent cells on sterile coverslips.
b. Remove the coverslip from the medium and aspirate excess medium.
c. Add 100 μL of working solution, gently shake it to completely cover the cells,and then incubate at room temperature for 5-30 minutes.
d. Wash twice with medium, 5 minutes each time. Observation by fluorescence microscopy or flow cytometry.
Storage
-80°C, 1 year
Protect from light
Precautions
1. Please adjust the concentration of PKH 26 working solution according to the actual situation.
2. This product is for R&D use only, not for drug, household, or other uses.
3. For your safety and health, please wear a lab coat and disposable gloves to operate.

Reference

[1]. Fischer K, et al. The flow cytometric PKH-26 assay for the determination of T-cell mediated cytotoxic activity. Methods. 2003;31(2):135-142.
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