Gradient Thin-Layer Chromatography of Nucleotides

Mark the start with a pencil on a PEI Cellulose sheet (dimensions as in Protocol 3.1.2) and apply the samples with a microliter syringe or a pipet. 

Develop the sheet with H2O for about 1.5 h to a height of 16 cm, then dry it and continue development with Solvent 1 to a running distance of 13 cm. Move the sheet in methanol for some minutes and dry it again. Then do the same procedure with Solvent P, followed hy a third run with Solvent 1 . 

If lithium chloride gradient is used, develop the sheet ascending for 2 min with Solvent 2, and then for 6 min with Solvent 2 and last up to 16 cm with Solvent 2 . 

Depending on the nucleosides, which of the solvent systems gives the best results should be verified. 

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