2.4. MSD immunoassay
The MSD multiplex immunoassay was used to measure the total IgE as well as specific IgE-levels. This method is based on the U-plex protocol of MSD (Rockville, MD, USA),14 but was adapted specifically for IgE-measurements, using biotinylated allergens and IgE standards from Radim Diagnostics (Freiburg im Breisgau, Germany).