Which specimens require warm collection?

• A. Cryoglobulin
• B. Cryofibrinogen
• C. Cold Agglutinin
• D. All of the Above

Answer: (D)

Specimens containing temperature-sensitive proteins or antibodies must be kept warm to prevent in vitro changes that would affect the test result. Cryoglobulins are proteins that precipitate when cooled, so drawing into a pre-warmed tube and keeping the sample at body temperature (about 37°C) from collection through serum separation is essential. Cryofibrinogen behaves similarly, forming precipitates when cooled, which means it also requires warmth during collection and transport. Cold agglutinins are antibodies that can cause red cells to clump at low temperatures, so blood must be drawn and handled warm to avoid any in vitro agglutination before analysis. Because each of these specimens needs warmth to preserve the true in vivo state, all of the above are collected warm.