The EldonCard ABO-Rh Home Blood Typing Test Kit is an easy-to-use home test complete with everything you need to type one person. The alcohol swab is included. All you have to do is supply the blood! The EldonCard will determine both ABO and Rhesus type. Each test kit will identify the blood type for one person. This home blood test is FDA-approved for educational use. Blood type test results can be read within 2 minutes.
NOTE: The test is not for medical use, such as the determination of transfusion.
In 1900 Landsteiner described the ABO blood type system, which depends on the presence or absence of two antigenic structures, A and B and on the presence or absence in the blood plasma of the corresponding antibodies Anti-A and Anti-B. The combination of the antigens and the antibodies is genetically determined. The antigens are present at birth, whereas the antibodies develop during the first year of your life. You will never find the same antigen and antibody in the blood of an individual. Thus if for example your blood group is A , it does not contain Anti-A . Landsteiner's discovery caused extensive serological investigations and a large number of other blood type systems were disclosed, among which the Rhesus system described in 1940 is the most important.
The Rhesus blood group system, which is also genetically determined, is much more complicated than the ABO system. The most important part of it is the D-antigen and the corresponding antibody Anti-D. The D-antigen is also attached to the surface of the erythocytes, (red blood cells) and a person with this antigen present is called D-positive or Rhesus-positive. You will never find Anti-D in the plasma of a Rhesus-positive person.
If the D-antigen is absent, the blood type is called D-negative or Rhesus-negative. Normally you will not find any Anti-D in the plasma of Rhesus-negative persons, but in case D-positive erythrocytes are introduced into the blood of a D-negative person, Anti-D will develop. This may happen in two situations, either during pregnancy of a D-negative mother with a D-positive foetus, or If a D-negative patient receives a transfusion of D-positive erythrocytes.
Normally there is no direct connection between the blood circulation of the mother and the foetus, but they are only separated from each other by a very thin membrane. During the birth or an abortion small ruptures often appear in the delicate membrane and erythrocytes from the foetus will enter the maternal circulation. The D-antigens of the child will cause the D-negative mother to produce Anti-D (the mother is then immunised) and then Anti-D will remain in the mother's blood plasma throughout the rest of her life.
In the case of a later pregnancy with a D-positive foetus, the antibody will pass the membrane, enter into the foetal circulation and attack the D-positive erythrocytes of the child. The erythrocytes will disappear, and the hemoglobin released from the erythrocytes is degraded into highly toxic bilirubin. A condition of anaemia and jaundice in the child will develop. This situation can be prevented by giving every D-negative female who has a pregnancy or an abortion an injection of Anti-D immunoglobulin in the course of the first 48 hours of the birth or abortion. This Anti-D will attack and destroy the few D-positive fetal erythrocytes present in the maternal blood before the process of immunisation takes place.
A similar immunisation will take place and Anti-D will become present in the patient's plasma in the case of a transfusion. A later transfusion with D-positive erythrocytes will cause these erythrocytes to be attacked by the Anti-D with life-threatening consequences. At the very least the patient becomes immunised against future donations of D erythrocytes, which creates difficulties in finding compatible future blood donors. The situation can be prevented by never giving a D-negative person a transfusion with D-positive blood.
A blood donor must therefore be of the same ABO-type and D (Rhesus)-type as the recipient. Otherwise corresponding antigens and antibodies will be brought together in the recipient's bloodstream, and in the worst case the recipient's antibodies will attack the transfused erythrocytes and glue these together (agglutination) and then subsequently destroy (lyse) them with a potentially life-threatening result.
Conventional blood grouping at a hospital blood bank takes place after the plasma has been removed by centrifugation. Using an Eldoncard the blood is not centrifuged, and the blood plasma will be applied onto the Eldoncard along with the red cells. In very rare cases the presence of the blood plasma might cause false agglutinations. Such false agglutinations could be observed in any one of the circular fields, including the control field. Actually the control field was made part of the Eldoncard for the purpose of disclosing such rare false agglutinations.
If an agglutination or an agglutination like pattern is observed in the control field, the reading in the other fields is not valid. In such cases it is recommended to dilute the blood with an equal volume of water. The diluted blood can then be applied onto the card as previously. In most cases the re-testing of the blood will show a control field without any agglutination, and the reading in the other fields can then be trusted. In extremely rare cases it might be necessary to wash and centrifuge the blood and conduct a conclusive blood grouping using a suspension of washed red cells.
From a clinical point of view the Rhesus or Rh system is by far the most important system other than ABO. Rh incompatibility is the main cause of hemolytic disease of the newborn, and a major cause of transfusion reactions. As however hemolytic disease of the newborn is not being considered in detail in this book, and as the other disease associations of the system are few and relatively unimportant, only a brief account of the system will be given here.
The principal antigen of the system Rh0 or D, was discovered by Landsteiner and Wiener (1940). Subsequently, very numerous other associated antigens were discovered, and considerable controversy arose both as to notation and as to the theoretical interpretation of the uncontroversial observations of geneticists. This is not the place to discuss the controversy and for the purpose of this book the CDE notation of Fisher (Race, 1944) will be used, and its genetic implications of closely linked genes will be assumed. Only the main features of this very complex system will be described. On this basis the principal antigen of the system is known as D, determined by a gene D, the allele d of which behaves as an amorph very closely linked to the Dd locus are two other loci each characterized by a pair of major alleles Cc and Ee respectively. Each of these four genes gives rise to a correspondingly named antigen.
Them are thus eight possible chromosomic combinations of genes, all of which are known to exist, but of which CDe cDE, cDe, and cde are the commonest.
Incompatibility with respect to the D antigen it, as already mentioned, the main cause of hemolytic disease of the newborn, but Cc and Ee incompatibilities are rare causes, as they am also of transfusion reactions. Unlike the antibodies of the ABO system, each of which is universally present in persons lacking the corresponding antigen, antibodies to the Rh antigens are virtually never found except as a result of immunization by pregnancy or transfusion, and reactions appear only at a second exposure to the antigen. This applies also to all the other blood-group systems except the ABO. Very few searches have been made for any other kinds of disease associations of the Rh groups, and nearly all of these are confined to a comparison of the D-positive and D-negative types.
Rh blood type might also influence NK cell activity. While some studies have not found an association, other researchers have observed a higher natural NK cytotoxicity against target cells in individuals with Rh- blood type. It has recently been demonstrated that two human Rh glycoproteins can correct ammonium transport deficiency in mutant yeast cells. Rh proteins are therefore ammonium transporters - a role that, in vertebrates, has remained previously uncharacterized. These data herald a new era in Rh protein research, beyond their role as blood group antigens, and into the characterization of ammonium transport mechanisms, notably in the kidney.
Eldoncard A/S is a Danish company named after the Danish physician Knud Eldon who developed the blood grouping card in 1950. They were first commercially manufactured in 1954 and since that time, over 60 million have been produced. Eldoncards allow the user to determine whether their blood group is type A, O, B or AB, and whether they are rhesus positive or negative. They can also be used as identification cards or as driving licenses in some countries.
The cards are suitable for use outside the hospital blood banks in such cases as at the bedside just prior to a transfusion, in the practitioner's clinic, on remote locations such as ships and oil rigs, on the battle field, in the class room, in the private home, or in any emergency situation calling for a speedy and reliable test. To eliminate the risk of transfusion errors the German and French health authorities have ordered a mandatory bedside test just prior to any blood transfusion. The blood of the patient and the blood in the bags already brought to the bed of the patient are grouped with Eldoncards, and the transfusion will only take place if both cards show the same blood group for the ABO and the rhesus systems.
ELDONCARD A/S is the only company specialised in the manufacture of dry format cards for blood grouping. Health authorities in countries with advanced health care systems have approved the Eldoncards, which are used for many purposes and sold all over the world. To meet the needs of the various types of end-users, ELDONCARD A/S has developed a broad assortment of Eldoncards, packages containing Eldoncards, and bulk kits with Eldoncards for use in the clinic.
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