When the mixture is complex and incomplete separation is obtained with one dimensional chromatography then two-way or two-dimensional chromatography in two different solvents is employed to produce better resolution of the component spots.In this method the solution is spotted in the corner of a square or rectangular sheet of paper. The ascending or descending chromatography is carried out. When this is over, the paper is removed from the tank, dried, and turned through 90.Then the chromatogram is developed in a different solvent. This technique allows the path of the migration to be increased and also enables the partially separated components to be further separated in a solvent with characteristics different from those of the first. After the second development, the paper is removed from the tank. it is then dried and the spots are located on the paper with selective reagents.