Preparation of TLC plates

[karern]

I need to run an assay using TLC and we are going to use PEI cellulose membranes. The instructions we got were to wash the chromatograms by ascending chromatography in water, with a paper wick attached to the top. Then dry the plates, mark the origin etc and "groove" 1.5 cm wide channels into them.

What is this paper wick and how do we clip it on the plates?
Why do we need to wash them in water first?
How do we make the grooves?
How long does it take to wash a plate and dry it, for a 20x20 cm chromatogram?
I have never used this big TLC plates before, what do these chromatography tanks look like, so I can try and locate some in one fo the labs here?

Cheers, Karin

[lmh]

If you have to groove a lot of plates, you can get a workshop (if you have one) to make a template by cutting lines through a thinnish (2mm?) aluminum plate, and fixing strips of aluminium across two adjacent edges. The tlc plate can be held up against these two edges, and the whole thing turned aluminium-plate-upwards (probably holding the tlc against a glass plate on the other side. Then you score lines through the cuts in the aluminium plate. I used to use a small spatula for the job, but it's awful on fibrous cellulose plates. You might be able to buy templates like this, I've never tried.

No idea about the wick thing though.