Stains-All Stock Solution:
0.1% Stains-All (Sigma) w:v in formamide
Store at 4_ C, and protect from light (use a dark bottle).
Stains-All Working Solution:
Sigma recommends diluting the stock 1:9, but I use it at 1:4 to getfaster staining.
Dilute the stock in 75% 20 mM Tris pH 8, and 25% isopropanol. I havealso diluted the stock 1:4 in straight formamide and this also gives goodresults.
Put the working solution in a WIDE-MOUTH, dark bottle and store at 4°C.
Add ~400 mL of the working solution to a 9x13" pan.
Carefully remove gel from plates and place in stain. I remove one plateand then put the bottom edge of the other plate in the stain and slowlywork the gel off into the pan.
Make sure the gel is submerged, cover the pan with foil, and stain for~20-60'. The amount of time necessary to stain effectively is somewhatempirical, but will get longer as the working solution ages. You will needto remake the working solution every few months.
The RNA bands will stain a dark purple color that is mass dependent.1 mg is easily visualized and you can see downto about 50 ng, maybe less with O/N staining.
Pour the Stains-All solution from the pan back into the wide-mouth storagebottle.
Rinse the gel and pan in dH2O from the tap.
Fill the pan with dH2O and place under direct lightto destain the gel.
The gel should destain in ~60', but watch because the bands will alsodestain. It is finished destaining when the gel is clear (no longer purple)and the bands are sharp.
Transfer the gel to saran-wrap for photography. Let the excess waterrun off the gel and be sure to dry it carefully with kimwipes before coveringwith the top layer of saran-wrap.
NOTE: If you are in a hurry, put your gel in a clear pyrex pan for destaining.Place the pan on white blotter paper and put a desk lamp about 10-12" fromthe top of the pan. Watch closely... it will take ~15 minutes to destainand then your bands will start to disappear. I wouldn't recommend thismethod if you are trying to see faint bands.