Confirmation of the airborne occurrence of micron-size airborne pollen antigen carrying particles by immunoblotting.

We confirmed the existence of micron-size airborne particles carrying major pollen antigen of Cryptomeria japonica (Cry j l) and Lolium perenne (Lol p l) by means of an immunoblotting technique and examination by light microscopy. The size of the spots on a nitrocellulose membrane, marking the presence of antigen on the sampler's tape, varied considerably under light microscopic examination. Spots smaller than pollen grains and micron-size spots were observed together with large spots which seem to have been derived from intact pollen grains. The number of micron-size spots counted under a light microscope did not correspond with the number of spots from pollen grain observable with the naked eyes. This suggests other sources of airborne Cry j l particles than intact pollen grains alone.