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Protocols: ES Cell Culture - Gene Targeting - Protocols

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.