X-Gal Staining
(See also the protocol in “Current Protocols in Molecular Biology”)
1. Wash cells 2 X in Tris / PBS.
2. Fix in 4% paraformaldehyde in PBS; 15 minutes at Room Temp;
5 mL for 10 cm, 2 mL for 6 cm.
3. Wash 3 X in PBS / Tris (2nd wash 10 min).
4. Stain in X-Gal Solution; ~3 mL for 10 cm; stain several hours to overnight at 37C.
Solutions
1 X PBS:
4 % paraformaldehyde: dilute 20 % paraformaldehyde into 1 X PBS
Coloid developer (X-Gal Solution):
X-Gal 1 mg / mL (Stock: 50 mg / mL in DMF)
K4Fe(CN)6 5 mM (Stock 100 mM)
K3Fe(CN)6 5 mM (Stock 100 mM)
MgCl2 1 mM (Stock 1 M)
In 1 X PBS / Tris
100 mM KxFe(CN)6:
K4Fe(CN)6 4.2 g (100 mM)
K3Fe(CN)6 3.3 g (100 mM)
Add 100 mL 1 X PBS / Tris
20 % paraformaldehyde (pfa):
pfa 100 g
hot (60 – 65C) water 300 mL
20 X PBS 25 mL
Bring to 450 mL with DI H2O
Add NaOH until clears (pH 7-8)
Cool to 4C
Filter with 0.45 um filter and aliquot