Methods that allow reduction of the electroosmotic flow (EOF) to a negligible value in a simple and reproducible manner are of great interest for many potential applications in capillary electrophoresis. In the absence of an EOF the apparent mobility is equal to the effective mobility, making possible identification on the basis of literature values of mobility. In the present work we characterize two dynamic coatings based on the addition of water soluble additives to the running buffer (i) poly(dimethylacrylamide) and (ii) a combination of poly(vinyl alcohol) and cetyltrimethylammonium bromide. The performances of the two systems are evaluated under different experimental conditions.