Silver Staining Protocol for DNA - EDTA solution concentration missing (Jul/13/2006 )

hi u all
I'm setting up a silver staining assay taking advantage of a internet protocol.
The following protocol was used based on the staining improvements of BASSAM . The desilver and impregnation steps were modified.

1. Fix 30 min 10% acetic acid (v/v)
2. Rinse 3 tex2html_wrap_inline5162 2 min water (bidest.)
3. Impregnate 20-30 min AgNO tex2html_wrap_inline5184 (1 g/l)
+ 100 tex2html_wrap_inline5160 l 37% formaldehyde per 100 ml
4. Rinse 20 s H tex2html_wrap_inline4879 O (bidest.)
Thoroughly wash the gel surface and back of the gel
5. Develop 2-5 min 2.5% NaCO tex2html_wrap_inline5184
(visual control) + 100 tex2html_wrap_inline5160 l 37% formaldehyde per 100 ml
+ Na tex2html_wrap_inline4879 S tex2html_wrap_inline4879 O tex2html_wrap_inline5184 tex2html_wrap_inline5186 5H tex2html_wrap_inline4879 O (2 mg/liter)
6. Stop 10 min 2% (g/v) glycine
+ 0.5% EDTA disodium salt solution
7. Impregnate 10 min 5% (v/v) glycerol
8. Dry overnight room temperature
Has anyone try it?
In step 6 there is a 0.5% EDTA disodium salt solution but there is no evidence about the solution concentratiion. Someine knows the conc.?
Regards
Fede

it appears to be calling for a final concentration in the stop solution of 0.5%. you could add 10 ml/ 100 ml final volume of 5% edta.