Sample Selection in Proteomics Research: Serum or Plasma?

In proteomics research, choosing serum or plasma as the analysis sample depends on the research purpose and specific experimental design. Serum and plasma are both liquid components of blood, but they differ in composition, which may affect the results of proteomic analysis.

1. Plasma

Plasma is the yellow liquid component of blood, making up about 55% of total blood volume. It is separated from whole blood before coagulation and contains water, electrolytes, nutrients, waste products, gases, hormones, and plasma proteins, including albumin, globulins, and clotting factors. Because plasma contains clotting factors, an anticoagulant is needed during collection to prevent blood from clotting.

2. Serum

Serum is the liquid portion separated from coagulated blood, which is plasma without clotting factors. It does not contain fibrinogen and other clotting factors but still contains a large amount of proteins (such as albumin and globulins), hormones, electrolytes, and other components.

3. Choosing between Serum and Plasma

1. Research Purpose:

The choice between serum or plasma depends on the specific needs of the research. For example, if the study involves the coagulation system, plasma may be a more suitable choice because it contains clotting factors. Conversely, if the focus of the research is on proteins not involving clotting factors, serum may be a better choice.

2. Differences in Protein Composition:

Differences in protein composition between plasma and serum can affect the results of proteomic analysis. Some proteins may be more abundant in plasma, while others may be more common in serum.

3. Experimental Design:

The design and objectives of the experiment will also influence the choice. For instance, using plasma may require consideration of the effects of anticoagulants, whereas using serum does not.