Establishment of monoclonal antibodies of BW10kDa distinguish it from Fag e 2 related to anaphylaxis

•Anti-BW10kDa Monoclonal antibody (mAb) distinguished 2S albumin Fag e 2.•Homology of whole sequence of BW10kDa to Fag e 2 was more than 50 %.•Western blotting to seed extract using type 1 anti-BW10kDa mAb revealed two bands.•Epitopes recognized by type 1 mAbs were near BW10kDa C-terminal region.•10 kDa band was the C-terminal subunit of BW10kDa(15 kDa) after protease digestion. BW10kDa, which is a buckwheat (BW) allergen, belongs to the 2S-albumin protein family, akin to Fag e 2. Detailed analyses of BW10kDa were lacking until this study. Herein, we conducted these analyses using monoclonal antibodies (mAbs) to recombinant BW10kDa (rBW10kDa). We successfully generated anti-rBW10kDa mAbs capable of distinguishing between Fag e 2 and BW10kDa. These mAbs were categorised into two types (type 1 and type 2) based on their reactivity to BW plant seed extracts in western blot analyses. Type 1 mAbs revealed two bands (15 kDa and 10 kDa), while type 2 mAbs showed a single band (15 kDa). Spot analyses using these mAbs confirmed that type 1 mAbs recognised epitopes near the C-terminal region, with the 10 kDa band representing the C-terminal subunit cleaved by protease. The mAbs targeting rBW10kDa enabled to assess the concentration of BW10kDa in wild type and also in diagnostic buckwheat extracts.