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FORENSIC SCIENCE Serology. Forensic File #2. A murderer thinks that they can wash away all signs of blood by using everyday household cleaners and then painting over the spots with new paint. Will this work? Explain your answer. Parts of Blood and Blood typing.
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Forensic File #2 • A murderer thinks that they can wash away all signs of blood by using everyday household cleaners and then painting over the spots with new paint. • Will this work? Explain your answer.
Parts of Blood and Blood typing • Turn in your Intro to Serology Quiz • Today’s assignments: 1. Parts of Blood webquest/typing practice- on computer cart 2. Finish Animal blood comparison microscope lab- tables 2 or 3 3. Blood type probability problems- on front table • Animal blood lab, parts of blood webquest and probabability problems all due today
What are some characteristics of blood? • Plasma--fluid portion of the blood (55%) • Serum--liquid that separates from the blood when a clot is formed
Characteristics of blood • Cells (45%) • Erythrocytes--red blood cells; responsible for oxygen distribution • Leukocytes--white blood cells; responsible for “cleaning” the system of foreign invaders • Thrombocytes--platelets; responsible for blood clotting
What is the difference in blood types? • ABO blood groups--based on having an A, B, both or none of the factors on the red blood cell • Rh factor--may be present on the red blood cell; positive if present and negative if not
Blood typing facts • Around 1900, Karl Landsteiner discovered the 4 different types of human blood based on the presence/absence of antigens found on red blood cells • In 1940 Landsteiner and Weiner discovered the Rh factor. 85% of Caucasians, 94% or Black Americans, and 99% of all Asians are Rh positive
Back to blood typing • Antigen--a substance found on a red blood cell • Antibody--a substance that reacts with an antigen • Agglutination--clumping of red blood cells; will result if blood types with different antigens are mixed