Difference between Plasma and Serum

Blood is a fluid connective tissue which travels throughout the body by transporting all the necessary elements like nutrients, oxygen, and other metabolic wastes. It is also involved in the regulation of the body’s temperature and the pH by interacting with acids and bases. Blood is largely composed of RBC – red blood cells, WBC -white blood cells, plasma, and serum. Both plasma and serum are the main components of blood and are routinely used in blood group test experiments for determining the patient’s blood group.

What is Plasma?

Plasma is the medium of the blood, in which different types of blood cells including red blood cells, white blood cells and other components of blood are suspended. Plasma composed of serum and clotting factors.

What is Serum?

The serum is the liquid or undiluted part of the blood which lacks clotting factors. Hence it is formed after the coagulation of the blood.

Here are some great differences between the two main components of blood cells – Plasma, and Serum.

Difference between Plasma and Serum



A clear, straw-colored, liquid portion of the blood.

An undiluted fluid, the extracellular portion of blood.

Composed of serum and clotting factor.

It is the part of the blood which lacks clotting factor.

Acquired after centrifuging blood with the anticoagulant.

Acquired after centrifuging of coagulated blood.

Anticoagulant is required to obtain plasma from the blood sample.

Anticoagulant is not required to separate the serum from the blood sample.

Consists 55% of total volume of blood.

Less volume in comparison to plasma.

Comparatively easier and less time is required to separate the plasma from the blood sample.

Difficult to separate serum from the blood sample. It is a time-consuming process.

Contains fibrinogen.

Lack of fibrinogen.

Consists of 92% water with Proteins, Salts, Lipids, and Glucose.

Consists of 90% water with dissolved hormones, proteins, minerals, and carbon dioxide.

Has 1.025g/ml density

Has 1.024g/ml density.

Have more shelf life. It preserved even for 10 years.

Have less shelf life. It can be preserved only for few months.

Plasma is the main medium for excretory product transportation.

An important source of electrolytes.

Cells are freely suspended in plasma.

Cells are attached together by clot formation.

For more information related to the blood, serum, and plasma, visit BYJU’S.

Practise This Question

The outgrowth of Hydra is termed as