The differentiation solution for carmine staining according to Best in your variant consists of a mixture of ethanol and methanol diluted with about 50% water. This solution is used to selectively remove the excess dye from certain tissue components to achieve better contrast between the stained structures.

After staining with the carmine solution and counterstaining with hematoxylin, the tissue sections are briefly immersed in or panned over this differentiation solution. The alcoholic solution selectively removes the excess dye from the tissue components, brightening the background and improving the contrast between the stained structures. Differentiation solution is an essential step in Best's Karmin staining to obtain sharp and clear images of glycogen and other cellular structures in tissue sections.