Organ donation is the act of physically removing an organ or tissue from the donor and inserting it into the recipient. There are many organs that can be transplanted including the heart, intestines, kidneys, liver, skin and bone marrow among others. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original EssayA new organ may be needed in case one fails or is affected by a disease. For example, if someone has a fatal liver problem, a transplanted liver can save their life. Before an organ can be transplanted into a recipient, a long process of organ matching takes place: the blood groups of the donor and recipient are matched, the tissue typing process takes place, and the donors are selected. The donor and the recipient must share the same blood type because otherwise the antibodies present in the recipient's blood will react by attacking the antibodies present in the introduced blood. Furthermore, the tissues must be as similar as possible to decrease the chances of rejection. There are no two people on this planet, other than identical twins, who share exactly the same types of tissues. Tissue typing is a group of procedures to determine the histocompatibility antigens (molecules found on all cells in the body; each person has a unique set of them) on a person's cells or tissues. Human lymphocyte antigens (HLA) are the most widely used antigens for histocompatibility. They are grouped into two classes: Class I is found on all cells, Class II is found only on B lymphocytes, macrophages, monocytes, dendritic cells and endothelial cells. The typing process is performed on blood samples, easily taken from a vein. Specific antibodies in the blood sample react to specific antigens. Specific antibody preparations bind to specific histocompatibility antigens. There are specific laboratory instruments used to detect specific antibodies that bind to cells. Class II antigens can be discovered by mixed lymphocyte reaction (MLR) or polymerase chain reaction (PCR). In the first, lymphocyte duplication occurs when there is a mismatch and can be detected using a specific test. The second is a DNA test that can determine the presence or absence of antigens by checking whether the genes for the antigens are there. Tissue typing greatly reduces the chances of rejection by the recipient's immune system, even if he or she will have to take immunosuppressant drugs, which reduce the strength of the immune system, for the rest of his or her life. Please note: This is just an example. Get a custom paper from our expert writers now. Get a custom essay Donors are selected based on their age, habits and medical history. They must be at least 25 years old, have not smoked for at least 4 weeks before donating, must meet drug screening requirements and must be healthy individuals (people with heart disease, diabetes, lung problems and cancer cannot donate). organs).