Plasma VS Serum Differences and Comparison Guide. by Arshad. The difference between plasma and serum is that is that Plasma has clotting factors in it while Serum does not contain clotting factors. Clotting factors are those factors that leads our blood to clot. Also, serum and plasma are present within the blood stream. Serum osmolality is affected by the concentration of blood chemicals like chloride, sodium (Na), proteins, bicarbonate, and glucose. The blood urea nitrogen (BUN) measurement is important for calculating serum osmolality. Specific therapies and toxins that affect an individual’s fluid balance should also be evaluated with serum osmolality. A serum osmolal gap (osmotic gap) may also be calculated. It is the difference between measured and calculated (estimated) osmolality results. In order to calculate the osmolal gap, tests for blood sodium, blood urea nitrogen (BUN), and glucose must be performed to calculate the expected osmolality. Your blood can be separated into four components, one of them being plasma. The other three are: red blood cells; white blood cells; platelets; Plasma makes up about 55 percent of your blood. It It has more protein molecules. It has a lesser amount of proteins. It has less dissolved carbon dioxide. The fluid has more carbon dioxide content. Plasma has more dissolved oxygen. It has less dissolved oxygen. They constitute a small percentage of the total extracellular fluid. Tissue fluid constitutes a higher percentage than plasma. Let us look at the differences between them. Plasma. Platelets. Definition. It is a straw-coloured liquid which has blood cells suspended in them. Platelets are small colourless fragments found in the blood. It is a type of blood cell. Function. It has clotting factors and other important protein molecules suspended in it. Plasma is the liquid phase of whole blood. Plasma contains all clot formation factors such as prothrombin, fibrinogen and platelet-activating factor. If a clot reaction occurs, the blood matrix is then called serum. Therefore, the main difference between plasma and serum is the latter's lack of clot formation agents. The difference between serum and plasma is minimal. Serum has the same composition as plasma, but it does not contain fibrinogen, which is a type of fibrin precursor protein used in blood clotting. Create an account to view solutions 1Ov4l.