1.   For positive controls, sections containing rectal carcinoma and normal mucosa were employed and for negative controls the primary antibodies were excluded.

2.   Negative controls were obtained by omitting or exchanging the primary antibodies.

3.   Each section was treated with a drop of primary antibody.

4.   Additionally, a solution of the purified primary antibody absorbed with PT-gliadin was tested.

5.   Each set of sections included a positive colorectal carcinoma control, and a negative control in which the primary antibody was omitted.