Copper Staining of SDS-PAGE Gels

After electrophoresis, the gel is submerged without fixing into Soln. A (about 10 ml per milliliter of gel) for 5 min with gentle agitation. The gel is washed with ddH20 for 2-3 min. The protein bands appear clear, whereas the rest is milky opalescent. This effect is best visible using a black background. 

The authors describe the same detection hmit if compared with Coomassie, hut in our opinion, copper staining is less sensitive 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. 

A further option to stain by copper is the application of copper(ll) phthalocyanine 3,4, 4 ,4 -tetrasulfonic acid(CPTS). 

Stain the gel for 1 h in Soln. B, pour off the liquid and destain by several changes of Soln. C until the background is colorless. 

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