Which lipoprotein forms a creamy layer during ultracentrifugation?

Which lipoprotein forms a creamy layer during ultracentrifugation?

• A. LDL
• B. HDL
• C. Chylomicrons
• D. VLDL

Answer: (C)

Understanding how ultracentrifugation separates lipoproteins hinges on density: the more triglyceride and the less protein a particle has, the lower its density. Chylomicrons carry the most triglyceride and little protein, making them the least dense of the common lipoproteins. When a plasma sample is spun at ultracentrifugation speeds, these least-dense particles rise to the top, forming a creamy layer that’s rich in fat. The other particles—VLDL, LDL, and HDL—are denser and settle below that creamy layer, with HDL being the densest due to its higher protein content. Therefore, the creamy top layer is characteristic of chylomicrons.

Understanding how ultracentrifugation separates lipoproteins hinges on density: the more triglyceride and the less protein a particle has, the lower its density. Chylomicrons carry the most triglyceride and little protein, making them the least dense of the common lipoproteins. When a plasma sample is spun at ultracentrifugation speeds, these least-dense particles rise to the top, forming a creamy layer that’s rich in fat. The other particles—VLDL, LDL, and HDL—are denser and settle below that creamy layer, with HDL being the densest due to its higher protein content. Therefore, the creamy top layer is characteristic of chylomicrons.