The saccharine test for assessing mucociliary clearance in the nose is the most practicable method. As the used sodium salt of saccharine is well water soluble, there is suspicion of interference with the very delicate two-layer-system of mucus or transport merely in the periciliary fluid, thus bringing about methodical errors. This is avoided by using inert tracers such as radioactively tagged ion exchange resin particles, which on the other hand must be observed with expensive equipment. A synthesis of both methods is demonstrated by using saccharine loaden ion exchange resin particles. The validity of the test is proven in vitro and in vivo.