Immunogold electron microscopic localization of timothy grass (Phleum pratense) pollen major allergens Phl p I and Phl p V after anhydrous fixation in acrolein vapor.

We used the vapor phase of acrolein as an anhydrous fixative for timothy grass pollen in an immunogold double-labeling localization study of two different major allergens, Phl p I and Phl p V. More than 48 hr of fixation were needed for the subcellular pollen structures to be satisfactorily stabilized. The immunoreactivity of acrolein-fixed pollen allergens was not destroyed even after prolonged acrolein fixation. By immunoblotting, the two allergens differ in their immunological and structural characteristics. Electron microscopic localization traced the allergens at least partially to different subcellular pollen compartments.