Biomedical Engineering Reference
In-Depth Information
The authors describe the same detection limit if compared
with Coomassie, but in our opinion, copper staining is less sen-
sitive and has the main disadvantage that it is impossible to dry
copper-stained gels. On the other hand, proteins are not denatu-
rated by fixation and staining and can be eluted from gels in high
yield.
References
Lee C, Levin A, Branton D (1987) Anal Biochem 166:308
Variant
A further option to stain by copper is the application of copper(II)
phthalocyanine 3,4
,4
,4
-tetrasulfonic acid(CPTS).
B . 5g copper(II) phthalocyanine-3,4
,4
,4
-tetrasulfonic acid,
Solutions/Reagents
tetrasodium salt, in 100 ml 12 mM HCl
C 2mM HCl
Stainthegelfor1h in Soln. B, pour off the liquid and destain by
several changes of Soln. C until the background is colorless.
References
Bickar D, Reid PD (1992) Anal Biochem 203:109
2.4.4 Staining of Glycoproteins and Polysaccharides in Gels
2.4.4.1 Staining with S
CHIFF
's Reagent (PAS Staining)
PAS staining (periodic acid - Schiff's reagent) colors compounds
with vicinal hydroxyl groups, i.e., mainly oligosaccharide side
chains in glycoproteins, glycolipids, and nucleic acids. The sen-
sitivity and stability is much lower than the silver staining Proto-
col 2.4.2.5 but more specific.
A
30% methanol (v/v), 10% acetic acid (v/v) in ddH
2
O
Solutions/Reagents
B
7.5% acetic acid (v/v) in ddH
2
O
C
1% sodium metaperiodate (w/v) in Soln. B
D
Schiff's reagent: 1% basic fuchsin (magenta, rosaniline; C.I.
42510) (w/v), 1.9% sodium bisulfite in 0.15 NHCl. The solution
is stored overnight in a refrigerator, and then a spatula of
charcoal is added. After shortly stirring, the charcoal is filtered
off. The colorless filtrate is stable for 4 weeks in a refrigerator.
E
1% sodium bisulfite (w/v) in 0.1 N HCl
F
0.01% 8-anilino-1-naphthalenesulfonic acid (ANS), ammo-
nium salt, (w/v) in E
Shake the PAGE gel three times in Soln. A to remove SDS for 1 h.
Then it is oxidized with Soln. C for 1 h at 4
◦
C,followedbyatleast
four washings with Soln. B.
