Dog Serum

If the proper anticoagulant treatment is not applicable, the whole blood in vivo will naturally coagulate under the action of fibrinogen after being collected in vitro, and the liquid part after centrifugation is called blood serum. Except for fibrinogen and clotting factors, serum contains all metabolites produced by the body, such as proteins, hormones, biomarkers and circulating nucleic acids. Serum is easier to obtain than plasma and is considered to be a standard sample for clinical testing. Serum is also a type of sample selected by many laboratories. Due to the different composition of serum and plasma, the concentrations of many analytes in plasma and serum are different, so the experimental evaluation results should pay attention to the type of sample source to prevent major evaluation errors.

Figure 1. Outcomes of the survey on the use of serum and plasma tubes
(Source: lebani M, et al. 2020)

The use of serum has the following advantages. First, there is less cellular contamination. After centrifugation there is almost no cellular component in the serum, whereas plasma still contains a large number of red blood cells, white blood cells, platelets and cellular debris. Second, some measurements are more stable, and studies have shown that the stability of glucose in serum is better than that in plasma samples stored at room temperature. Third, there is no anticoagulant, so as to reduce the interference caused by this kind of substance. For example, EDTA and heparin have an effect on immunoassay. Serum can also be used for clinical treatment, and the most common use is as an antitoxin or antivenom. One way to treat Ebola infections, for example, is to inject sera containing passive antibodies from survivors of previous infections.

The study of serum is called serology, the broad definition of serology refers to the study of humoral reactions, mainly serum reactions, and more strictly speaking, serology is the study of serum immune response. At present, there is basically only one purpose for the development of serological diagnostic test, which is to determine the reaction conditions so that it can provide the best diagnostic accuracy for a specific classification in a single measurement.