An antibody produced with a C-terminal region of DBT as an immunogen recognizes a DBT antigen. Extracts were prepared from the heads of adult wild-type flies (W), dbtS flies (S), and pero; timo flies (PoTo), and these were subjected to SDS-PAGE and immunoblot analysis. Blots were probed first with preimmune serum (A) and then with the same dilution of serum from the rat after injection of GST-DBTCim, an immunogen derived from the C terminus of DBT (B). Chemiluminescent detection revealed the DBT antigen of the expected molecular mass (∼46 kDa) only with application of the immune serum. Blots probed with the preimmune serum were exposed long enough to reveal the nonspecific background, which did not show a 46-kDa protein.