By BioNanoNet
Immunogold labelling is used to compensate the lack of knowledge about air filter efficiency regarding retention rates as far as major allergy triggers (e.g. birch, grass, ragweed pollen, or domestic cat) are concerned. Filter and filter systems are still tested with standardized mineral dust (e.g. “Arizona Road Dust”) but the findings of these research methods are not representative in the context of allergens and pathogenic germs. Immunogold electron microscopy, a very sophisticated method, enables the location of specific proteins responsible for an allergic reaction. Because of their high spatial resolution and the used small gold particle size (approximately 10 – 60 nm), this method is typically applied for transmission electron microscopy (TEM). Due to the sample size, they have to be examined in a scanning electron microscope (SEM). An iterative sample preparation process was established by the ZFE Graz to achieve a strong signal (high gold particle concentration) at the exact position where the allergen is present while the background is not being labelled. By means of monoclonal antibodies it is possible to detect specific proteins under investigation. This technique gives us the opportunity to accurately locate the allergenic or pathogenic germ proteins and to obtain information about the distribution of particle sizes where these proteins are present. The FFG Coin Aufbauprojekt Aeropore is concentrating on this topic, in close cooperation with the OFI (Österreichisches Forschungsinstitut für Chemie und Technik) in Vienna on the development of a filter testing system at pilot-plant scale. Reference project: FFG Coin Aufbauprojekt Aeropore
