What are the differences between microcolumn gel test and traditional hem-agglutination test?
Traditional hem-agglutination test: The macroscopical red cell agglutination reaction of the red cell antigen and the corresponding antibody occurs in the medium of saline water in the tube or on the slide.
Microcolumn gel test: The macroscopical red cell agglutination reaction of the red cell antigen and the corresponding antibody occurs in the medium of gel in the cavity of the microtubes.

How to define the classification of the microcolumn gel immunoassay?
The classification of gel: the neutral gel; the specific gel; the antihuman globulin gel.
The classification of the method for microcolumn gel test: direct hem-agglutination test; antihuman globulin test; indirect hem-agglutination test (Forward and reverse indirect hem-agglutination test); hem-agglutination inhibition test.

The classification of the usage of microcolumn gel:
Used for the blood group serology test of blood transfusion; the immunoassay laboratory diagnosis of HDN etc.; the antibody detection of platelet and leukocyte; the detection of virus, bacterium etc. pathogenic microorganism.

What are the characteristic and advancement of the microcolumn gel immunoassay?
It is simple, accurate and sensitive. Few volume of sample is needed. Furthermore, it is standardization and safe. The result can be conserved for a long time.

The definition and etiological of the hemolytic disease of the newborn (HDN)
When the blood groups of the fetus and pregnant women are incompatible, the fetal red cells will enter the maternal circulation and induce the corresponding antibody production. This sort of IgG antibody can cross the placenta and act on the fetal red cells to lead to haemolysis of different degree and usually cause the fetal death. If the fetus survives, the antibody comes from mother will continue inducing haemolysis of newborn after birth, even lead to the physiological handicap or death of the newborn if serious. This is called Haemolitic disease of the newborn (HDN).
The basic etiopathogenisis of HDN is that the red cells of the fetal enter the maternal circulation. One half of the fetal blood group genes are from mother and the other half are from father. If the genes come from father are just the missing part of mother, the antigens on the fetal red cell membrane which are coded by the father’s genes will stimulate mother to produce the corresponding antibodies which belong to the kind of IgG immune antibodies. They can cross the placenta. Once the antibodies cross the placenta and enter fetal circulation, they will probably combine with fetal red cells and destroy the cells, and then the haemolysis will be induced. This will cause fetal anemia, hydrops, abortion, fetus death, prematurity and HDN.

Why the newborns whose mothers’ blood group is O are more prone to suffer from the HDN?
Group A(B) fetus of group O mother are more prone to suffer from the HDN, this condition occupied 95%, because that the IgG is the dominant class of anti-A and anti-B of group O serum. The IgG antibodies of ABO blood system, which have smaller molecular weight and higher titer, produced by mothers of group O after the stimulation of A or B antigen can easily cross the placenta. But after stimulated by blood group antigens, the mother of group A or B mainly produces the ABO antibodies of IgM which have big molecular weight and can not cross the placenta. So the fetus of group O mothers are at higher risk for ABO hemolytic disease of the newborn (HDN) than the fetus of group A or B mothers.

What does the antepartum immuno-hematology test contain?
The conventional detection of antepartum immuno-hematology contains: 1. The ABO blood grouping for parents. 2. The Rh blood grouping for parents. 3. The irregular antibodies screening for pregnant women (Most of the irregular antibodies are incompletely antibodies and IgG antibodies which can cross the placenta. The antibody screening and identification for the pregnant women can preliminarily judge the possibility of the HDN.) 4. Identify the antibodies of the subject whose result of antibody screening is positive. 5. The titer test of alloimmunity antibody.

What is the purpose of antepartum immuno-hematology test?
The antepartum immuno-hematology can prognose the possibility of HDN, and detect the alloimmunity antibody of the pregnant women simultaneously. The blood grouping, antibody screening and identification, titer test of pregnant women, which can show whether the pregnant women are stimulated by the foreign antigens via the placental hemorrhage or other way and need specific immune globulin therapy (especially the Rh negative pregnant women), may prevent the blood transfusion accident and the problem of gravidity again in future.

What does the HDN immuno-hematology test contain after parturition?
It contains the blood grouping of newborn, Coombs' test (DAT, elusion test and free test)
1. The positive result of DAT indicates that the red cells of infant have been sensitized by the blood group antibody.
2. The positive result of elusion test indicates that the HDN is certified. The antibodies on the sensitized cells are released by heating. Identify the specificity of the antibodies in the elusion by the standard red cells.
3. The positive result of free test indicates that there are ill-matched antibodies, but the red cells are not sensitized. The newborn has the possibility of getting HDN.

The clinical significance of the irregular antibody test?
a. The antibody screening of donor can prevent the blood containing irregular antibody from being transfused to the patient and avoid the hemolytic transfusion reaction induced by the cells destroying. And the blood waste can decrease. The blood sample containing irregular antibody can be prepared into antibody serum which is applied to detect rare blood group.
b. The antibody screening of recipient is helpful for choosing blood. It ensures that there is enough time to choose compatible blood to prevent the hemolytic transfusion reaction induced by transfusing the blood containing the corresponding antigens of the antibodies of recipient.
C. The antibody screening of pregnant women is helpful for detecting the irregular antibody as early as possible. The prevention and therapy of HDN in the duration of pregnancy can decrease the harm of the irregular antibody to the fetus or newborn and improve the physical quality of the fetus or newborn.