Py-BODIPY-NHS ester is a small molecular dye with strong UV absorption that can be used to label living cells and immobilise cells.

BODIPY lipid droplet dyes can effectively pass through the cell membrane, entering the cell to specifically stain lipid droplets with polar lipids. This feature makes them suitable for labeling both live and fixed cells [2].

Cell staining experiment
I. Solution preparation:
1. Preparation of mother solution: dilute 1mg Py-BODIPY NHS ester with 382 μL anhydrous DMSO to prepare a 10 mM stock solution; (it is recommended to store at -20 ℃ or -80 ℃ in the dark after aliquoting)
2. Preparation of working solution: dilute the stock solution with preheated serum-free cell culture medium or PBS to prepare a 1-10 μM Py-BODIPY NHS ester working solution; (select the appropriate working solution concentration according to the experimental requirements, and prepare it for use immediately)
II. Cell staining operation steps:
Suspended cells:
1. Collect cells by centrifugation and wash twice with PBS, 5 minutes each time. The cell density is 1×106/mL;
2. Add 1 mL of Py-BODIPY NHS ester working solution and incubate at room temperature for 5-30 minutes;
3. Centrifuge at 400 g for 3-4 minutes and discard the supernatant;
4. Add PBS to wash the cells twice, 5 minutes each time;
5. Resuspend the cells with 1 mL of serum-free medium or PBS and observe them using a fluorescence microscope or flow cytometer.
Adherent cells:
1. Culture the adherent cells on a sterile coverslip;
2. Remove the coverslip from the culture medium and remove the excess culture medium;
3. Add 100 μL of dye working solution, gently shake it to completely cover the cells, and incubate for 5-30 minutes;
4. Aspirate the dye working solution, wash 2-3 times with culture medium, 5 minutes each time, and observe them using a fluorescence microscope or flow cytometer.

The above information is based on published literature. Experimental procedures should be appropriately modified to meet specific research demands.

DMSO: 20 mg/mL (46.93 mM), Sonication is recommended.