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

Exercise 39

Microscopic examination of stools mixed with Sudan III and glacial acetic acid and then heated will show small orange-red droplets that represent:

A. Fatty acids and soaps

B. Fatty acids and neutral fats

C. Fatty acids, soaps, and neutral fats

D. Soaps

Step 1 of 2

Increase of fat in feces is called steatorrhea. To detect the fecal fat, microscopic examination is performed on feces.

• Qualitative procedure is performed to measure to the cholesterol ester and extra unstained phospholipids

• The followings are the lipids which are included when performing microscopic examination:

o Neutral fats also called as triglycerides

o Fatty acid salts

o Fatty acids

o Cholesterol

• The above lipids can be viewed when staining the feces with the following dyes

o Sudan III

o Sudan IV

o Oil red O

• Neutral fats can be viewed when staining it with the Sudan III

o It is viewed as large “orange-red droplets” at the cover slip edge

• Fatty acids and soaps cannot be stained with the Sudan III directly. Hence, acetic acid is mixed and heated

o It is viewed as small “orange-red droplets” and it indicates the fatty acids and the fatty acids produced by neutral fats and soaps

Therefore, when performing the microscopic examination with the feces which is stained first with Sudan III and acetic acid then heated shows the small “orange-red” droplets that indicates the “fatty acids, soaps, and neutral fats”. Hence, the correct answer is option.