Which color is used for stat serum determinations in chemistry?

• A. Gold
• B. Orange
• C. Red
• D. Royal Blue

Answer: (B)

For time-sensitive chemistry tests, speed in obtaining serum is crucial. The orange-top tube contains a thrombin-based clot activator that accelerates clot formation, allowing serum to be ready much quicker. That rapid clotting enables faster serum separation and quicker results for STAT determinations. In contrast, gold-top tubes (SST) also yield serum but rely on gel separation and take longer to clot, which delays STAT results. Red-top tubes have no clot activator, so they depend on natural clotting time and are slower. Royal Blue tubes are used for trace elements or toxicology and aren’t the standard choice for routine stat serum chemistry. So the orange top is the best fit for STAT serum determinations.