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.