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FORENSIC SCIENCE PAPER No.: 12 FORENSIC BIOLOGY AND SEROLOY MODULE No. 14 EXAMINATION OF BLOOD
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http://www.britannica.com/EBchecked/topic/69685/blood/35429/Laboratory -examination-of-blood www.bloodjournal.org/ http://www.bbc.com/news/health-32530339 www.crime-scene-investigator.net/blood.html https://www.centralia.edu/academics/forensicscience/.../DBloodID.ppt
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FORENSIC SCIENCE PAPER No.: 12 FORENSIC BIOLOGY AND SEROLOY MODULE No. 14 EXAMINATION OF BLOOD
Glossary A ABO Blood Group ABO blood group system, the classification of human blood based on the inherited properties of red blood cells (erythrocytes) as determined by the presence or absence of the antigens A and B, which are carried on the surface of the red cells. People may thus have type A, type B, type O, or type AB blood
B Blood Blood is a bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells Blood contains antibodies, nutrients, oxygen ,etc required for proper functioning of the body.
E Electrophoresis Electrophoresis is a technique used in laboratories in order to separate macromolecules based on size. The technique applies a negative charge so proteins move towards a positive charge. This is used for both DNA and RNA analysis.
L Luminol Test The luminol chemiluminescence reaction is responsible for the glow of lightsticks. The reaction is used by criminalists to detect traces of blood at crime scenes. The luminol solution is sprayed where blood might be found. The iron from the hemoglobin in the blood serves as a catalyst for the chemiluminescence reaction that causes luminol to glow, so a blue glow is produced when the solution is sprayed where there is blood.The blue glow lasts for about 30 seconds before it fades, which is enough time to take photographs of the areas so they can be investigated more thoroughly
R RH factor
FORENSIC SCIENCE PAPER No.: 12 FORENSIC BIOLOGY AND SEROLOY MODULE No. 14 EXAMINATION OF BLOOD
Rhesus (Rh) factor is an inherited trait that refers to a specific protein found on the surface of red blood cells. If your blood has the protein, you're Rh positive — the most common Rh factor. If your blood lacks the protein, you're Rh negative.
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Blood Spatter Pattern Analysis Bloodstain pattern analysis (BPA) is one of several specialties in the field of forensic science. The use of bloodstains as evidence is not new; however, the application of modern science has brought it to a higher level. New technologies, especially advances in DNA analysis, are available for detectives and criminologists to use in solving crimes and apprehending offenders. The science of bloodstain pattern analysis applies scientific knowledge from other fields to solve practical problems. Bloodstain pattern analysis draws on the scientific disciplines of biology, chemistry, mathematics and physics. If an analyst follows a scientific process, this applied science can produce strong, solid evidence, making it an effective tool for investigators, although care does need to be taken when relying on bloodstain pattern analysis in criminal cases. A report released by The National Academy of Sciences calls for more standardization within the field. The report highlights the ability of blood spatter analysts to overstate their qualifications and the reliability of their methods in the court room.
Experiments with blood have shown that a drop of blood tends to form into a sphere in flight rather than the artistic teardrop shape. This is what one would expect of a fluid in freefall. The formation of the sphere is a result of surface tension that binds the molecules together. This spherical shape of blood in flight is important for the calculation of the angle of impact (incidence) of blood spatter when it hits a surface. That angle will be used to determine the point from which the blood originated which is called the Point of Origin or more appropriately the Area of Origin.
FORENSIC SCIENCE PAPER No.: 12 FORENSIC BIOLOGY AND SEROLOY MODULE No. 14 EXAMINATION OF BLOOD
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An upward moving bloodstain showing proper placement of eclipse
A single spatter of blood is not enough to determine the Area of Origin at a crime scene. The determination of the angles of impact and placement of the Area of Origin should be based on the consideration of a number of stains and preferably stains from opposite sides of the pattern to create the means to triangulate.
A blood droplet in freefall has the shape of an oscillating sphere. Should the droplet strike a surface and a well-formed stain is produced, an analyst can determine the angle at which this droplet struck the surface. This is based on the relationship between the length of the major axis, minor axis, and the angle of impact. A well-formed stain is in the shape of an ellipse (see figure above). Dr. Victor Balthazard, and later Dr. Herbert Leon MacDonell, realized that the width-length ratio of the ellipse is the sine of the impact angle. Accurate measurement of the stain thus allows easy calculation of the impact angle.
FORENSIC SCIENCE PAPER No.: 12 FORENSIC BIOLOGY AND SEROLOY MODULE No. 14 EXAMINATION OF BLOOD