Difference between Blood and Serum

Key Difference: The blood is an important part of the human body. The blood is part of the circulatory system, the center of which is the heart. The heart pumps the blood to all parts of the body, which in turn helps transport necessary nutrients and oxygen to the cells of the body. Serum is part of the blood that is left over after the red blood cells, the white blood cells, the blood platelets, and clotting factors have been removed from the blood.

The blood is an important part of the human body. In fact, about 7% of the human’s body weight is blood, which in most humans comes out to about 5 liters of blood. The blood is part of the circulatory system, the center of which is the heart. The heart pumps the blood to all parts of the body, which in turn helps transport necessary nutrients and oxygen to the cells of the body. It also helps remove the waste products and carbon dioxide that the cells have produced. In addition to all this, the blood also helps regulate temperature, the pH balance, and water balance.

The blood is made up of three different parts: the red blood cells, the white blood cells, and the blood platelets. The red blood cells are the one that actually carry the oxygen, nutrients, waste products and carbon dioxide. The white blood cells are the ones that fight off infections and help heal wounds. The blood platelets help the blood to clot. All the three, i.e. the red blood cells, the white blood cells, and the blood platelets are suspended in the blood plasma.

The plasma contains various dissolved proteins, glucose, clotting factors, antibodies, mineral ions, hormones and carbon dioxide. The plasma is an important factor in carrying the red blood cells, white blood cells, and the platelets. The plasma is also important in the process of removal of excrement. It also acts as the protein reserve of the human body, and protects the body from infections and other blood disorders. It also keeps electrolytes balanced and helps maintain a proper ph balance in the body.

The blood plasma is basically what is left of the blood, after the red blood cells, the white blood cells, and the blood platelets have been removed from it. However, the blood plasma still has the clotting factors such as fibrinogens. Once, the fibrinogens are removed from the plasma, the solution that is left over is known as serum. Hence, the serum is basically blood – the red blood cells – the white blood cells – blood platelets – anti-clotting agents.

The blood serum still contains all the proteins that are not used in blood clotting, as well as all the electrolytes, antibodies, antigens, hormones, and any exogenous substances such as drugs and microorganisms.

The serum has a variety of uses. It is primarily used in various types of diagnostic tests, including blood typing. Serum is also important for the self-renewal of embryonic stem cells in combination with the cytokine leukemia inhibitory factor. Additionally, serum is useful for immunotherapy, where the serum taken from the blood of people who have survived an infectious disease can be used in treatment for other as it already contains the antibodies for that pathogen.

Comparison between Blood and Serum:

	Blood	Serum
Description	Blood is a reddish fluid that is part of the circulatory system that helps transport oxygen and nutrients to the cells and the removal of waste from those cells.	Serum is part of the blood that is left over after the red blood cells, the white blood cells, the blood platelets, and clotting factors have been removed from the blood.
Part of	The circulatory system	Blood, which is part of the circulatory system
Made up of	Red blood cells White blood cells Blood platelets All floating in blood plasma	Electrolytes Antibodies Antigens Hormones Any exogenous substances such as drugs and microorganisms.
Color	Red, due to presence of red blood cells.	A clear, yellowish color, as the red blood cells which give the blood its color have been removed.
Function	To provide oxygen and nutrients to parts of the body To remove waste nutrients and carbon dioxide. To regulate body temperature To maintain a constant pH and water balance	Primarily used in various types of diagnostic tests, including blood typing. Important for the self-renewal of embryonic stem cells in combination with the cytokine leukemia inhibitory factor. Serum is useful for immunotherapy, where the serum taken from the blood of people who have survived an infectious disease can be used in treatment for other as it already contains the antibodies for that pathogen.