How many times can I reuse Ponceau S? - (Dec/07/2009 )

Hi, I've been using Ponceau S to stain my membranes and I've noticed that is not as sensitive. I won't see bands that I detect in the WB. Is this because I've reused it too much?

I think everytime I poor the TBST from the blot and add the PS, there is still a little bit left that get mixed with it and that may be the problem.

Any thoughts on this?
Thanks

The dye does wash/dilute out slowly - if you make some fresh solution you will notice that it is much darker red. I use it probably about 40-50 x before changing, though I have seen protocols saying to change it every 10 x.

also keep in mind that immunostain is a lot more sensitive than ponceau stain (or coomassie, for that matter, probably even more than silver).

Thanks!!