Chromatography Forum

Hello everybody.

We have superdex 200 10/300 GL column. After few changes of filter on the upper side of the column half of milliliter of the gel has been lost.

I would like to ask how can I fulfill this small gap? If I add some sephadex g-50 for example?

thank you for your advice!

I can't say anything about the wisdom of adding Sephadex G-50 to the top of the column. I don't think it would contribute much to the separation due to the much larger particle size as compared to superdex 200. I do have a question though. Why would you change that filter instead of reversing the flow direction and cleaning with sodium hydroxide? I've used a superdex 10/30 column for years without having to open it. If the back pressure starts to rise, the cleaning procedure I just mentioned always fixes it. On some of those columns you can just lower the plunger on top so that it makes contact with the gel bed. Check and see if that's possible with your column.

I can't say anything about the wisdom of adding Sephadex G-50 to the top of the column. I don't think it would contribute much to the separation due to the much larger particle size as compared to superdex 200. I do have a question though. Why would you change that filter instead of reversing the flow direction and cleaning with sodium hydroxide? I've used a superdex 10/30 column for years without having to open it. If the back pressure starts to rise, the cleaning procedure I just mentioned always fixes it. On some of those columns you can just lower the plunger on top so that it makes contact with the gel bed. Check and see if that's possible with your column.

Thank you very much for your assistance.
I didn't change the filter, that was another person. I'm just trying to fix the problem when column has a gap between cap and gel. In this situation everything changes: small molecules go faster (diffusion) in solution.
Thats why it was necessary to add a bit of g-50 to fill the gap.