IgE binding to sugar beet pollen proteins detected by immunoblotting. Numbers 1–14 refer to individuals listed in Table 1. NC is number 16 (negative control). Pool is sera from 1–14 pooled together. Lanes are marked with a black dot for individuals that according to Table 1 have both positive SPT and specific IgE to sugar beet pollen (except nr 13 had positive SPT but no specific IgE). After separation of sugar beet pollen proteins by SDS-PAGE (15%), blotting transfer was performed to PVDF membranes. Sera from test persons diluted 1:6 were used as primary antibody; HRP-labelled secondary antibody directed to human IgE was used to visualize bands by ECL.