Halo-Ligand Staining of Cells for Protein Condensate-Interaction Studies Using Single-Molecule Imaging

1 After creating the cell lines2 expressing the HaloTag protein of interest and Halo-H2B, 3 prepare the halo ligand staining reagent 4 separately for both of them. 5 Rinse the cells with two milliliters of PBS. 6 Add halo ligand containing media 7 and incubate them at 37 degrees Celsius 8 with 5%carbon dioxide for one hour.

9 After removing the staining media, 10 rinse the cells four times with PBS 11 and incubate them with fresh media devoid of halo ligands. 12 After four such rinse incubation cycles, 13 transfer the cover slip with cells 14 to a microscope stage compatible chamber 15 with sterile forceps. 16 Add phenol red-free media to the chamber before imaging.