b-Galactosidase Color Assay for Cultured Cells
1. For transient expression assays, wait until 2 days after
the transfection to begin the color assay. Aspirate the media and
rinse the cells twice with PBS.
2. To fix the cells, add 5 ml of a 0.5% Glutaraldehyde in
PBS (pH 7.2) solution; incubate @ room temp. for 10 minutes.
3. Rinse the cells twice with PBS.
4. Stain the cells in [5 mM Potassium Ferricyanide, 5 mM
Potassium Ferrocyanide, 2 mM MgCl2, and 1 mg/ml X-gal] overnight in
the dark @ room temp.
Notes: The 25% Glutaraldehyde stock solution is stored @ -20o C.
200 mM stocks of the potassium solutions are prepared in PBS and
stored in the dark @ 4o C.
0.01% NaDOC and 0.02% NP-40 may be included in the staining
solution, but they are not essential.