Conducting a blood test for blood type and Rh factor - important examination based on the determination of species specific proteins on the surface of red blood cells called antigens. From that, how is the combination of them, are 4 main groups. These values are individual and are retained unchanged lifelong.
Why and when you need analysis
Donate blood for analysis to find out which group it belongs to, and a Rhesus factor has everyone needs. For the first time the procedure is performed at birth. Then, if it becomes necessary, inspection may be performed again. Most often it is needed in the planning of pregnancy or in connection with hospitalization. Results of blood tests Rh factor needed for those who are engaged in or awaiting a transplant donation bodies, if there is a large blood loss, anemia in severe or other hemolytic diseases.
Total identified 4 groups: A, B, O and AB. The determining factor belonging to a particular group is the presence of two antigen located on the surface of red blood cells. These values are unchanged. At birth, the inherited parameters mother or father. However, there are cases of changes in the newborn. This is due to the fact that he can not inherit the parent gene, and their more distant ancestors.
When calculating the group at the same time set the Rh factor. It is a protein that is found on the surface of red blood cells. If the material of the donor revealed his presence, it testifies positive Rh factor. If it is not - a negative.
The results of these analyzes are important, especially for those people whose activities are related to the risk of massive blood loss.
This fire service personnel and police, military.
The results obtained are entered in their personal affairs and to individual chips. These people often need emergency blood transfusion, and is not always possible to take samples and conduct additional analyzes.
Knowledge of indicators, if necessary, emergency transfusion can save a person's life. Therefore, if the physician gives the direction of the analysis, it must hand over.
How to prepare
Properly prepare the body for blood donation on blood type will help compliance with simple rules:
- Analyzes sit on an empty stomach. The last meal should be no later than 8-10 hours before the blood test.
- On the morning of the appointed day are allowed to drink only water.
- Per day from the diet should be removed fatty and spicy food, alcoholic drinks.
- An hour before the procedure is non-smoking.
- Before carrying out the analysis of the blood group and Rh factor can not overwork. It is necessary to reduce any stress both physical and mental, to avoid emotional tensions.
- Before you go to the lab room, you need to calm down and rest a few minutes.
- On the eve of the appointed day to take any medicines, you should inform your doctor.
a second procedure in the same facility may be recommended to confirm the resulting analysis. In an emergency, when you need urgent hospitalization, the analysis is carried out regardless of whether the patient has had time to prepare or not.
How is the study
A blood test is possible in laboratories of any medical institution. laboratory workers to determine the blood group of donor material is taken. After sending him to study.
The study took place in two directions simultaneously and lets you know the blood group to analyze and Rh factor. By determining antigens and specific antibodies can be set belonging to a different group. ABO system consists of two agglutinogens A and B and two antibodies - agglutinins plasma anti-A and anti-B.
For analysis of the results apply a few basic ways:
- Using standard erythrocytes. In this situation, to establish the donor group takes the material with three different groups. Occurrence of agglutination or adhesion to determine which group belongs to the test sample.
- Using izogemagglyutininovyh sera representing a set of antibodies to erythrocytes. If the sample contains antigens which then begins the process of forming an antigen-antibody reaction that starts gluing. The nature of the reaction to determine the ratio of the sample with one or another group.
- Using the antibodies produced in the laboratory. They may react with red blood cells agglutinogens on the surface. The nature of the reaction makes it possible to perform decoding.
Where are the blood on blood group
Blood for analysis to determine the type and Rh factor, is dealt from a vein in the elbow. Before it is applied above the elbow bandage contracting. Take the material using a syringe. The procedure is painless, does not cause discomfort and adverse reactions. Feels reminds shot.
Venous biomaterial is taken because it is the most informative. If a blood test for a group of finger, such a material does not provide a full picture of its composition.
Analysis done quickly. The result of the patient can get delivery day. If technicians are heavily loaded, then after a few days.
What happens next in the laboratory
All necessary parameters determined in the laboratory. To this end, a special technique was developed.
To determine the blood type and Rh factor derived biomaterial is mixed with a reagent which comprises a specific antibody.
On the basis of the prepared positioned 3 drops of blood from a single sample. To each is added dropwise a special test reagent: one - anti-A test, to the other - the test anti-B, and the third - the test reagent to establish Rh factor.
If the first drop appeared clots, t. E. there was a process of adhesion of red blood cells, it means that the antigen is present in the material A. If agglutination process does not come in the second sample, it indicates the absence of antigen B. If in the third sample was bonding, it confirms the presence of a positive Rh factor. The current pattern makes it possible to assert that the sample belongs to the group A and has a positive Rh factor.
Analysis is important.
Especially if there is an urgent need for transfusion.
Donated blood must be fully compatible with the recipient material. Otherwise, the risk of dangerous reactions during the procedure.
Decoding results
Analysis of blood type and Rh factor makes it possible to identify the presence in the sample under study specific protein and carbohydrate moieties. Those that are attached to the surface of red blood cells, called agglutinogens. And those that are a part of the plasma - is agglutinins.
Transcript analysis was conducted in accordance with membership of the group:
- First or O. As part of the plasma is detected only the presence of agglutinins alpha and beta. Agglutinogens group on the surface of red blood cells do not.
- The second, or A. On the surface of red blood cells found only agglutinogen A and a part of plasma there is only a beta agglutinin.
- The third or B. On the surface of blood cells revealed the presence of an agglutinogen B. A plasma - agglutinin alpha.
- Fourth or AB. On the surface of red blood cells - antigens A and B, and in the composition of the plasma no agglutinins.
To determine the Rh factor in the capacity to add a reagent material. Gently stir the mixture. To do this, the capacity of a little scroll. After a while saline is administered. The contents were stirred gently and visually evaluates the result of laboratory. The presence of red flakes solution suggests that the sample has a positive Rh factor. If the color of the solution is uniformly pink, and there is no residue, it indicates a negative result.
