Course title

Pre-requisite

Course description

Forensic science is the application of basic biological; chemical and physical science principles and technological practices to the purposes of justice in the study of criminal and civil issues. In this class; emphasis is on understanding the underlying scientific theories of forensic science; with special emphasis on the basics of chemistry. The class will build upon the student?s prior knowledge of biology and chemistry; using analytical chemistry techniques to analyze and identify trace evidence; including DNA. Students will evaluate the constituents of materials by organic; inorganic; and biochemical analysis; and use their academic and laboratory skills to develop a deeper understanding of science. This class prepares students to further their science education at the university level; and introduces them to the possibilities of a science related career. Major themes of study in this course are pathology; anthropology; odontology; ballistics; trace evidence; biological fluids; DNA; fingerprints; impression evidence; questioned documents and forensic psychiatry/psychology.
Lab 1
Identification of Heavy metal Poisons

Poisons can come from a wide range of sources: car exhausts; pesticides; medicines; alcohol; industrial wastes; etc. Although lead and arsenic have long been used as poisons; the heavy metals-mercury; cadmium; and copper-are showing up as poisons in more and more cases. Whatever the poison; the ultimate effect is the same: the drug withholds the oxygen necessary for life processes to continue.

Our environment is full of materials that contain lead and mercury. Lead is found in storage batteries; industrial paint; leaded gasoline; solder; ceramic glazes; and artist?s paint pigments. Mercury is found in electric apparatus; thermometers; batteries; medicine; fungicides; industrial waste; and contaminated fish. Both of these metals can build up in the body and cause damage. Lead affects the functioning of the blood; liver; kidney and brain. It will be deposited in the bones over a period of time; a dose of 0.5 grams can be fatal (the weight of a 1/5 of a dime in your hand).

Mercury concentrates in the brain tissue and destroys brain cells (neurons) causing blindness; convulsions; mental retardation and even death. The fatal dose is about 1 gram. Both of the heavy metal poisons damage proximal renal tubules of the kidney giving off a large amount of certain amino acids in the urine. Paper chromatography can be used to identify these amino acids in the urine by comparing the chromatograms and Rf values with those of known amino acids. Various samples of the same amino acid will have the same Rf values.

Lead poisoning produces alanine and B-amino isobutyric acid.

Mercury poisoning produces glycine; also called amino-acetic acid.

In order to determine what poison was administered to the victim; tests must be conducted on the evidence found at the scene of the crime: bottles; glasses; containers or powders. If heavy metal poisoning is suspected; one of the first tests carried out is the Reinsch test. A small amount of the metal specimen and hydrochloric acid are placed in a small piece of copper foil and heated on a hotplate. If arsenic; bismuth; mercury or silver are present a black or gray stain will be deposited in the copper foil. In the case of mercury; the foil becomes a shiny silver color (similar to the color of aluminum).

A second test can be carried out using dithizone. This chemical forms various colored salts depending on the metal being tested. When a mixture of dithizone; acetone; and water is added to lead; the green solution changes to red (forming a reddish-orange precipitate). When the dithizone solution is added to mercury; the green color changes to a dark orange color.

Part I. Urine Analysis

Materials
Unknown urine
Urine with alanine
Urine with glycine
Solution of butanol and acetic acid
Ninhydrin
Chromatography paper
Micropipettes
Pencil
Ruler

Procedure
1. Using one strip of chromatography; micropipette a solute drop of the unknown; glycine; and alanine urine samples on a solute line:

2. Run the chromatography using the solvent provided by the teacher and allow the chromatography to run half way up the paper. Remove the chromatography; mark the solvent line; and allow to dry.

3. Once dry; carefully dab the chromatography papers with ninhydrin using a micropipette. (WEAR GLOVES). Use a hairdryer to dry the strips (this will take a few minutes) and circle each solute component as they appear.

4. Fill in the Rf data table (in comp book) and determine the identity of the unknown amino acid in the urine. Staple chromatography paper into comp book; clean up your lab station.

1. What type of heavy metal poisoning does this indicate?

2. What solvent was used to run this chromatography?

3. Is this a polar solvent? If so; why was it used?

Lab 2
BLOOD TYPING LAB

I. First; you are going to type 4 people?s blood. Follow the chart below and determine the blood type of the four people. (everything goes in comp book ?)

1. Obtain well plates and toothpicks.
2. Put one drop for each person in each of the wells (A; B; and Rh).
3. Add the antibody serum to the corresponding well plate and check for agglutination.

BLOOD TYPE Anti-A Serum Anti-B Serum Anti-Rh Serum
A agglutination No agglutination N/A
B No agglutination agglutination N/A
AB agglutination agglutination N/A
O No agglutination No agglutination N/A
+ N/A N/A agglutination
- N/A N/A No agglutination

Write the agglutination or No agglutination in the boxes and then identify the person?s blood type.

Person Anti-A Serum Anti-B Serum Anti-Rh Serum Blood Type
Allender
Zornes
Saxby
Town

II. Mr. Currie; a fellow science teacher and ?supposed friend? of the other science teachers; had his home burglarized over the weekend. . The perpetrator(s) entered by breaking a window. The perpetrator(s) were obviously cut from the amount of blood found in the office. Eye witness accounts report that Allender; Zornes; Saxby and Town were seen around Currie?s residence that weekend. You will be given 5 blood samples to test; four of them are unknowns and the 5th is Currie?s. Determine which one; if any; could have committed the break in.

Person Anti-A Serum Anti-B Serum Anti-Rh Serum Blood Type
Currie
Unknown A
Unknown B
Unknown C
Unknown D
Unknown E

Analysis Questions:
1. Who would you arrest; if anyone; and why? Write one paragraph reconstructing what might have happened the night Currie?s home was burglarized; establishing mean motive and opportunity. Discuss how common certain blood types are in your answer
Further Questions for ?BLOOD TYPING? piece of mind
(Use Blood typing lab Introduction sheet in your binder)

1. What happens to red blood cells that agglutinated?

2. What is the difference between agglutinogens and agglutinins?

3. How are ABO blood types determined?

Answer the following questions (4-7) by showing your work with punnett squares
4. Could a man with an AB blood type be the father of a child with Type O blood?

15. Could a man with an O blood type be the father of a child with type AB blood?

6. Could a type B child with a type A mother have a type A father?

7. What are the possible genetic combinations of a child whose parents? blood types are A and B?

Rh Blood Group

8. Ms. Allender?s mom is Rh + and her dad is Rh-. You must do 2 punnet squares. What are the chances for an Rh+ child? Rh-?

9. How does erythroblastosis fetalis develop?

10. Under what conditions might a person with Rh- blood develop Rh agglutinins?

11. Why can Rh+ blood be given once to a non-sensitized person who is Rh-?

12. What is likely to happen to a donor?s cell if an Rh- person who is sensitive to Rh+ blood receives a transfusion of Rh+ blood?

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• LINT
• Integrated science

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Online / Virtual