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

Exercise 44

What is the recommended number of samples that should be tested to confirm a negative occult blood result?

A. One random specimen

B. Two samples taken from different parts of three stools

C. Three samples taken from the outermost portion of the stool

D. Three samples taken from different parts of two stools

Step 1 of 2

gFOBT (guaiac-based Fecal Occult Blood Test):

gFOBT is frequently used test to detect fecal occult blood.

• The test rely on “pseudoperoxidase activity” of hemoglobin

• When hydrogen peroxide is added with the hemoglobin, due to pseudoperoxidase activity ,the colorless compound is oxidized and produce a colored compound

• Patients are allowed to keep the specimen on the filter paper, which is guaiac-impregnated and sealed container are mailed to the laboratory

• In laboratory, specimen kept in the paper is allowed to dry before the test

• Prior to the confirmation of the negative result of occult blood, at least two sample taken from different parts of three stools are tested

Therefore, “two samples from different parts of three stools” are tested to confirm the negative occult blood result .Hence, the correct answer is option.