RESUMO
Objective To develop the colloidal gold immunochromatography test strip for qualitatively detecting the hemoglobin (Hb) in human feces. Methods Mouse anti-human Hb monoclonal antibody SPR-5 marked by colloidal gold was coated in glass fiber membrane, and then the mouse anti-human Hb SP-5 monoclonal antibody and goat anti-mouse IgG were immobilized in testing (T) line and control (C) line located in nitrocellulose membranes, respectively. With this double antibody sandwich technique and immunochromatography test, the Hb antigen would react with both antibodies coated in the T line and C line and cause two colour reactions if the detected sample was positive, whereas the antigen-antibody combination and colour reaction only showed up in the C line when the sample was negative. Results The minimum detection limit of this test strip for human Hb was 21 ng/mL and no cross reactions were found in chick Hb, rabbit Hb, sheep Hb, pig Hb and cow Hb. Conclusion The test strips can improve the detection rate of fecal occult blood obviously and avoid false-positive results.
