Blood serum is nothing but its plasma, devoid of uniform elements and fibrin. It is formed as a result of certain chemical reactions. There are two ways to obtain blood serum: by neutralizing fibrinogen with calcium ions and as a result of natural blood coagulation.
The process of obtaining it is called "defibrinization". Technologically, it looks like this: blood collected in a vessel spontaneously coagulates, turning into a continuous clot of fibrin. The latter captures the formed elements of the blood and, with prolonged standing, gradually squeezes yellow liquid out of it. This is blood serum.
The color of the serum is explained by the presence of a certain amount of bilirubin in it. Its increase indicates the presence of pigment metabolism disorders. Normal serum is clear. But after eating a little cloudy, which contribute to the admixture of droplets of fat. The surface tension of blood serum is much lower than that of water.
Normally, the concentration of proteins in serum ranges between six and eight percent. In its composition, it contains mainly albumin (4.5-6.5%) and globulin (1.9-2.2%). A change in the proportions of these protein compounds, as well as their quantitative fluctuations, are of great clinical importance. However, this issue has not yet been fully studied.
Refraction of serum practically does not change under the influence of physiological factors, such as the impact of hydrotherapeutic procedures or a normal meal. But prolonged fasting can lead to a decrease in serum protein levels. On the contrary, muscular work practically does not affect its refraction.
A drop in the amount of protein in the blood serum is noted in acute infectious diseases. At the same time, the level of protein compounds independently returns to normal during the recovery period. An exception is tuberculosis, in which the total amount of protein, in particular globulin, increases significantly.
As for the area of application, blood serum is most often used during biochemical analysis of blood, its research for the presence of infectious diseases, to assess the effectiveness of vaccination, as well as to determine the group.
Currently, two different methods are used in medical practice, one of which is the determination of a blood group using standard sera. To avoid errors, use exclusively active serums with a sufficiently high titer. Research is conducted in a room where the air temperature should not exceed 25 degrees Celsius. The results obtained must be evaluated no earlier than 5 minutes from the start of the study.
The technique of this procedure is as follows. Initially, it is necessary to determine the titer of the diluted serum, which should not be lower than one in three. For this purpose, two large drops are taken from each tube, which are applied to a flat surface. Then, obviously different red blood cells are added to each of these drops and mixed with serum. After five minutes, the last drop is determined, where the agglutination took place. This is the largest breeding. This process is called a “hemagglutinating serum titer”.
Next, one large drop of standard serum is pipetted onto a glass slide or plate using pipettes, after which it is connected with a glass rod with drops of blood. After five minutes, one drop of saline is added to each drop mixture, and then the results are already evaluated. That's all for the blood group determination process using standard sera.
Summarizing the above, it should be noted that today, blood serum is not only a necessary reagent, but also the main active ingredient of many drugs used to treat a large number of infectious diseases.