SCANNING ELECTRON-MICROSCOPY OF IMMUNOGOLD LABELED CAT ALLERGENS (FEL-D-1) ON THE SURFACE OF AIRBORNE HOUSE-DUST PARTICLES

This study investigated the ability of an immunogold labeling techniqu e to demonstrate the presence of Fel d 1 (domestic cat) allergens on t he surface of particles in samples of airborne house dust. Suspended p articulate matter was sampled from ten Norwegian households, five with and five without a domestic cat. The specimens were immunogold labele d and examined in the backscatter electron imaging mode of the scannin g electron microscope and in the transmission electron microscope. X-r ay microanalysis was also applied to execute element analysis of the s uspended particulate matter. The gold probe was mainly detected on car bon particles in the suspended particulate matter, both on small (<1 m u m) and larger carbon aggregates (1-10 mu m). The present method may be useful in studying the localisation of different allergens on airbo rne house dust particles of various sizes and composition.