competent cells - (May/22/2013 )

Dear all,

I always work with competent cells that I get from a stock of electrocompetent cells we purcharged a while ago, however someone is working rubidium chloride competent cells.
Now I wonder how does this work?
I looked a bit and came up with this, from wikipedia:
RbCl transformation for competent cells is arguably the compound’s most abundant use. Cells treated with a hypotonic solution containing RbCl expand. As a result, the expulsion of membrane proteins allows negatively charged DNA to bind.

I wonder what the role of rubidium chloride is in this? I understand the hypotonic part, but what has that to do with rubidium chloride?

if you make home-grown competent cells, there are a number of Cl salts. the Cl salts in the preparation help open up channels in the membrane.