Organ donation is the act of physically removing an organ or tissue from a donor and placing it in the recipient. There are many organs that can be transplanted, including the heart, intestine, kidneys, liver, skin and bone marrow. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essayA new organ may be needed if it fails or becomes ill. For example, if a person has a life-threatening liver problem, a liver transplant can save their life. Before an organ can be transplanted into a recipient, a lengthy organ matching process takes place: the blood types of the donor and recipient are matched, the tissue typing process takes place, and the donors are selected. The donor and recipient must share the same blood type because otherwise the recipient's antibodies present in the blood will react by attacking the antibodies present in the introduced blood. The tissues must also be as close as possible in order to reduce the risk of rejection. No two people on this planet, other than identical twins, share the exact same tissue types. Tissue typing is a group of procedures for determining histocompatibility antigens (molecules found on all cells in the body; each person has a unique set) on a person's cells or tissues. Human lymphocyte antigens (HLA) are the most used antigens for histocompatibility. They are grouped into two classes: classes I are found on all cells, classes II are found only on B lymphocytes, macrophages, monocytes, dendritic cells and endothelial cells. The typing process is carried out on blood samples, easily taken from a vein. Specific antibodies present in the blood sample will react to specific antigens. Specific antibody preparations bind to specific histocompatibility antigens. There are specific laboratory instruments used to detect specific antibodies binding to cells. Class II antigens can be detected by mixed lymphocyte reaction (MLR) or polymerase chain reaction (PCR). In the first case, lymphocyte duplication occurs in the event of a mismatch and can be detected by a specific test. The second is a DNA test that can determine the presence or absence of antigens by looking to see if there are genes for the antigens. Tissue typing greatly reduces the chances of rejection by the recipient's immune system, although they will have to take immunosuppressive drugs, which reduce the strength of the immune system, for the rest of their life. This is just a sample. Get a personalized article from our expert writers now. Get a personalized essay Donors are selected based on their age, habits and medical history. They must be 25 years or older, not smoke for at least 4 weeks before donation, comply with drug testing requests, and be healthy people (people with heart disease, diabetes, lung problems and cannot donate). organs).