The Vroman effect, named after Leo Vroman

Leo Vroman

Leo Vroman is a Dutch-American hematologist, a prolific poet mainly in Dutch and an illustrator. Vroman was born in Gouda and he studied biology in Utrecht. When the Nazis occupied the Netherlands on May 10, 1940, he fled to London. From there he traveled to the Dutch East Indies. He finished his...

, is exhibited by protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 adsorption

Adsorption

Adsorption is the adhesion of atoms, ions, biomolecules or molecules of gas, liquid, or dissolved solids to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. It differs from absorption, in which a fluid permeates or is dissolved by a liquid or solid...

 to a surface by blood serum

Blood plasma

Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...

 proteins. The highest mobility proteins generally arrive first and are later replaced by less motile proteins that have a higher affinity for the surface. A typical example of this occurs when fibrinogen displaces earlier adsorbed proteins on a biopolymer

Biopolymer

Biopolymers are polymers produced by living organisms. Since they are polymers, Biopolymers contain monomeric units that are covalently bonded to form larger structures. There are three main classes of biopolymers based on the differing monomeric units used and the structure of the biopolymer formed...

surface and is later replaced by high molecular weight kininogen. The process is delayed in narrow spaces and on hydrophobic surfaces fibrinogen is usually not displaced.