The procedure for determining blood groups by ABOIt consists in the identification of antigens A and B in erythrocytes using standard antibodies and the use of agglutinins in plasma or serum of the analyzed blood by standard erythrocytes. The technique was developed at the beginning of the 20th century and is still actively used in medicine. Determination of antigens A and B is carried out thanks to the anti-A and anti-B cyclones.
Donors always identify not only antigens.in erythrocytes, but also agglutinins in serum (plasma) using standard erythrocytes. Venous blood is used as a biomaterial. Before the study, you must abandon fatty foods for the day before the analysis and do not smoke for half an hour before passing the test. Blood groups are determined twice: first in the medical department, where material is harvested, and then confirmed by research in the laboratory.
The determination of blood groups by ABO isthe main test used in transfusiology. Also, a similar system of blood types is in some animals, for example, in chimpanzees, gorillas and bonobos.
In science there is a generally accepted view thatThe method of determining blood groups using the ABO system was first identified by Karl Landsteiner, an Austrian scientist, in 1900. Then he described three types of antigens in his work. For this, thirty years later he was awarded the Nobel Prize in medicine and physiology. Due to the fact that there was no close relationship between scientists before, it was later established that the Czech serologist, Jan Jansky, regardless of the research of K. Landsteiner, first described four human blood groups, but his research was not known to a wide audience. At present, it is the classification developed by J. Jansky that is applied in Russia and the republics of the former USSR. In the USA, William L. Moss created his similar work in 1910.
Blood type should be determined in the room withgood lighting with a temperature range of 15 to 25 degrees Celsius, since deviations from this norm may affect the results of the study. The initials and the patient's last name are written on the plate or plate. From left to right or in a circle put the standard notation groups (O (I), A (II), B (III)). Under them are placed drop by drop the corresponding sera with individual pipettes for each species. Then the patient's blood is added to them. The material for the study is taken from the earlobe or finger. This requires the technique of determining the blood group on the ABO system.
It is also legitimate to use red blood cells,in vitro after a clot has formed. It is necessary that the amount of serum was more than ten times the amount of blood added. After that, the drops are mixed with glass sticks (separately for each). Within five minutes, gently shaking the plate, watching the appearance of the hemagglutination reaction. It is found in the fact that small red lumps appear, then merging into larger ones. Serum at this time almost completely loses its color.
In order to eliminate false hemagglutinationsimple gluing of red blood cells, you need three minutes to add one drop of saline and check whether the agglutination persists. If yes, then it is true. All, the definition of blood groups on the ABO system is complete.
As a result, four reactions can occur:
The method of determining blood groups by the AVO system involves the simultaneous identification of the Rh factor (Rh).
The surface of the plate is pre-moistened andwrite on it "control serum" and "serum antiresus". Then under the inscriptions have one or two drops of the necessary reagents and add the analyzed material to them. To do this, you can also use blood from a finger (in the same amount as the volume of serum) or red blood cells remaining on the bottom of the tube after a clot appears (half the volume of serum). The choice of material does not affect the final result. Then the blood and serum are mixed with a dry glass rod, after which the reaction is expected to occur within five minutes. In order to eliminate false indications, an isotonic solution of sodium chloride (just a few drops) is added after three to four minutes. The determination of blood group by ABO and Rh is carried out very often.
If red blood cell agglutination in a drop withserum occurs, it indicates a positive blood Rh. According to statistics, Rh + is found in 85% of the world's population. The absence of it allows you to talk about Rh-negative affiliation. If agglutination appeared in the control serum, it means it has become unusable. Unfortunately, the algorithm for determining the blood group by the ABO system does not always work perfectly.
Inaccuracies in determining the affiliation of blood to a group depend on the following reasons:
Possible errors in determining the blood group of the ABO system in a cross way:
Errors associated with the biological specificity of the analyzed blood are divided into two types.
Let's consider each species in more detail.
Weak serums with a past shelf life or having a titer of less than 1:32 are capable of producing weak and late agglutination. The use of such reagents is unacceptable.
Use of unsuitable standard red blood cellsor sera prepared under non-sterile conditions and insufficiently preserved, leads to the appearance of “bacterial” agglutination, which is of a non-specific nature.
There are many popular assumptions aboutblood groups of the ABO system, which appeared immediately after its discovery in different world cultures. For example, in the 1930s, a theory linking blood type with a particular personality type gained popularity in Japan and some other countries. Similar theories are popular today.
There is also an opinion that a person with group A is subject to a heavy hangover, O is associated with good teeth, and group A2 with the highest level of IQ. But such statements are not scientifically proven.
We reviewed the determination of blood groups by the ABO system using standard sera.
