To prepare the reagent used for mucin clot determination of synovial fluid, water is mixed with which acid?

To prepare the reagent used for mucin clot determination of synovial fluid, water is mixed with which acid?

• A. Glacial acetic acid
• B. Hydrochloric acid
• C. Sodium hydroxide
• D. Sodium chloride

Answer: (A)

The test relies on how mucin in synovial fluid responds to an acid to form a visible clot. Acetic acid, when diluted with water, creates a dilute acetic acid reagent that causes mucin to coagulate and form a firm clot in normal synovial fluid. This specific interaction is why glacial acetic acid is used—the acetic acid solution provides the right chemical environment to bring out the mucin network without overly damaging it. The other substances wouldn’t produce the same mucin-precipitation effect: hydrochloric acid would alter the pH differently and may affect mucin in an undesirable way, sodium hydroxide would raise the pH, and sodium chloride is not an acid and won’t induce the mucin clot.

The test relies on how mucin in synovial fluid responds to an acid to form a visible clot. Acetic acid, when diluted with water, creates a dilute acetic acid reagent that causes mucin to coagulate and form a firm clot in normal synovial fluid. This specific interaction is why glacial acetic acid is used—the acetic acid solution provides the right chemical environment to bring out the mucin network without overly damaging it. The other substances wouldn’t produce the same mucin-precipitation effect: hydrochloric acid would alter the pH differently and may affect mucin in an undesirable way, sodium hydroxide would raise the pH, and sodium chloride is not an acid and won’t induce the mucin clot.