Which statement best describes the principle of the SSA precipitation test?

• A. It detects protein in urine but is more specific than dipstick
• B. It detects lipids
• C. It precipitates protein and is less specific than dipstick
• D. It uses colorimetric detection of ketones

Answer: (C)

The principle being tested is that sulfosalicylic acid causes proteins in urine to precipitate, producing turbidity. When you add SSA to a urine sample, any protein present tends to form a visible precipitate, so the test is a general measure of total protein rather than a specific protein type. Because it responds to all urinary proteins (albumin, globulins, and other proteins like Bence Jones proteins), it is less specific about which protein is present compared with the dipstick method, which mainly detects albumin. That combination—protein precipitation with SSA and broad protein detection but lower specificity than dipstick—matches the described principle.