A refrigerated stool sample would be unsuitable for this test.

• A. Fat analysis
• B. Ova and parasites
• C. Urobilinogen
• D. All of the above

Answer: (B)

Detecting parasites in stool relies on seeing fragile forms that can deteriorate quickly outside the body. Trophozoites and some delicate parasite stages are easily damaged by refrigeration, which can kill or alter them and make identification impossible. Because freshness is essential for accurately spotting these organisms, a refrigerated stool specimen is unsuitable for ova and parasites testing; labs typically require a fresh sample or a specimen preserved with a specific fixative to preserve parasite structures.

Fat analysis and fecal urobilinogen testing are not as strictly dependent on immediate freshness; they can often be performed on samples that have been refrigerated or preserved. That’s why refrigeration would not render those tests unusable, and it rules out the idea that all the tests would be unsuitable.