Serum has the role of maintaining the normal viscosity, pH, and osmotic pressure of the blood, and can provide the body with essential nutrients, hormones, and growth factors. The definition of serum is generally divided into two kinds, one is the plasma after blood coagulation, removing fibrinogen and certain coagulation factors; the other is the plasma after removing fibrinogen. Common types of serum are generally fetal bovine serum, calf serum, rabbit serum, chicken serum, pig serum, horse serum, other animal serum, and synthetic serum substitutes. Serum has the role of maintaining the normal viscosity, pH, and osmotic pressure of blood. It consists mainly of water and various chemical components such as albumin, triglycerides, total cholesterol, and ghrelin. Serum contains various plasma proteins, fats, carbohydrates, growth factors, hormones, etc. that promote cell growth or inhibit growth activity to achieve physiologic balance. If you need to use serum treatment, you should choose the right serum under the guidance of a doctor, and follow the doctor’s instructions to standardize the use of the serum, so as not to delay the condition.