Blood carries oxygen and nutrients, removes waste, supports immune defense, and helps control bleeding. Its components work together, but they have different jobs.
Understanding those components is useful when discussing treatments made from a blood sample, including platelet-rich plasma and platelet-rich fibrin.
Plasma: the liquid component
Plasma is the liquid portion of blood. It is mostly water and contains proteins, electrolytes, nutrients, hormones, and other dissolved substances.
It transports blood cells and carries materials throughout the body. Plasma proteins also help maintain fluid balance, support immune function, and participate in clotting.
Plasma is not the same as serum. Serum is the liquid remaining after blood has clotted and the clot has been removed; its composition differs because clotting has consumed or removed certain components.
Red blood cells: oxygen transport
Red blood cells, also called erythrocytes, contain hemoglobin. This protein binds oxygen in the lungs and helps deliver it to tissues.
Blood also transports carbon dioxide back toward the lungs for removal. Much of that carbon dioxide travels in the form of bicarbonate rather than simply being carried unchanged by hemoglobin.
Red blood cells give blood its characteristic color.
White blood cells: immune defense
White blood cells, or leukocytes, help recognize and respond to infection, injury, and other threats.
Major types include neutrophils, lymphocytes, monocytes, eosinophils, and basophils. They perform different functions rather than acting as one uniform group.
Their presence in a processed blood preparation depends on the collection and separation method.
Platelets: clotting and signaling
Platelets are small cell fragments produced from larger cells called megakaryocytes, primarily in the bone marrow. They are not complete cells like white blood cells.
When a blood vessel is injured, platelets adhere, become activated, and help form a plug. They work alongside clotting proteins to help control bleeding.
Platelets also release growth factors and other signaling molecules involved in tissue repair. That activity is one reason researchers investigate platelet-based treatments.
Fibrin: part of the clotting framework
During clotting, the soluble protein fibrinogen is converted into fibrin. Fibrin forms a network that helps stabilize the clot.
This network is relevant to preparations described as platelet-rich fibrin or platelet-rich fibrin matrix. How it forms depends on the processing method and timing.
What happens when blood is processed?
Centrifugation separates components based on their physical properties. The resulting preparation depends on the collection tubes, equipment, settings, and other processing steps.
PRP, PRF, and PRFM should therefore not be assumed to contain identical amounts or types of blood components.
Understanding the ingredients explains the rationale for these treatments. Whether a preparation improves a particular concern still requires clinical evidence for that specific application.
Updated October 23, 2026.