Forensic Serology Blood
What Exactly is BLOOD?? • Fluid portion of blood= PLASMA • Primarily water and is 55% of the blood • Suspended in the plasma are solid materials, mostly types of cells: red blood cells, white blood cells, and platelets • This solid part of the blood makes up 45% of the blood • When blood clots when a protein in the plasma, FIBRIN, traps and enmeshes the red blood cells. • If you then removed the clotted material, a pale yellowish liquid called SERUM would be left. • RED BLOOD CELLS are called erythrocytes and are responsible for transporting Oxygen to the organs of the body
Brain Pop Blood Interactive Side of your Notes Write down 3 facts about blood while you watch!
Blood Facts • The average adult has about FIVE liters of blood inside of their body, which makes up 7-8% of their body weight. • There are about one billion red blood cells in two to three drops of blood. For every 600 red blood cells, there are about 40 platelets and one white cell.
Antigens and Antibodies • Antigens are a substance, usually a protein, that stimulates the body to produce antibodies against it • Antibodies (‘attackers’) are a protein in the blood serum that destroys a specific antigen
ABO Blood System • All human blood can be broken up into 4 groups based on its ANTIGENS. • A • B • AB • O
ABO Blood System • Type A blood has red blood cells that have A antigens on its surface • A antigens will make antibodies for B blood • If someone with type A blood received a transfusion of B blood, your body would produce antibodies for B and fight it, causing an allergic reaction and possibly death. This is called AGGLUTINATION • AGGLUTINATION means clumping or ‘glued together’ of the red blood cells
ABO Blood System Healthy Blood Cells Agglutinated Cells
ABO Blood System • Type B blood will create antibodies for A blood • Type AB blood is a mixture of both A and B antigens and does not create any antibodies • Type O blood does not have any antigens and creates antibodies for both A and B blood
Blood Transfusions Who can give you blood? People with TYPE O blood are called Universal Donors, because they can give blood to any blood type. People with TYPE AB blood are called Universal Recipients, because they can receive any blood type. Rh + Can receive + or - Rh - Can only receive -
Brain Pop ABO Blood Typing Interactive Side of your Notes Write down 3 facts about blood while you watch!
Rh Factor • Rh is also called the D Antigen, another protein that is found on some red blood cells • People who have the D antigen are considered Rh Positive • People who have Rh negative blood can develop antibodies against Rh positive blood • A pregnant woman with Rh negative blood who has a fetus with Rh positive blood could develop antibodies and attack the baby
Serum • Serum is part of the blood plasma and does not contain any blood cells • Serum includes all the proteins, antibodies, antigens • Serum is important because it contains antibodies (‘attackers’) • If a serum containing Anti-B (‘against-B blood’) is added to red blood cells of B blood, the blood cells will clump together or AGGLUTINATE • If a serum containing Anti-B is added to red blood cells of A blood, nothing will happen
Blood Typing • An unknown blood sample can be tested to see if it is A, B, AB, or O, by adding an Antiserum and observing if the cells agglutinate or clump • Example— • Antiserum B is added to unknown blood • The blood cells clump, therefore the unknown blood must have B antigens so it is either type B or AB • Then the same unknown is tested again with Antiserum A. • If it clumps again the unknown sample is type AB, if not then it is type B
Blood Typing Simulated Activity • Demo under doc camera if not enough supplies --or— In small groups
Blood Typing Game http://www.nobelprize.org/educational/medicine/bloodtypinggame/game/index.htm