Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 45

The immunochemical tests for occult blood:

A. Test for human globulin

B. Give false-positive reactions with meat hemoglobin

C. Can give false-positive reactions with aspirin

D. Are inhibited by porphyrin

Step 1 of 2

iFOBT (immunochemical Fecal Occult Blood Test):

• iFOBT is used to detect fecal occult blood and it is particularly for the globin part of human hemoglobin

• The test uses polyclonal anti-human antibodies of hemoglobin

• There is no restriction of diet and drug

• This test detects the lower gastro-intestinal (GI) bleeding, which indicates colon cancer

• The false-positive reaction are reduced because the test does not detects bleeding from other sources

• The hemoglobin from upper GI tract is degraded hence, blood is immunochemically nonreactive

• Blood from lower GI tract are not degraded much and hence the blood is immunochemically active

Therefore, immunochemical test for occult blood, tests the globin part of “human hemoglobin”. Hence, the correct answer is option.