May 4, 2015 Warm-up: Complete Q22 to 30 of the DNA Fingerprinting Review Packet Objective: SWBAT: w/85% accuracy – Use DNA evidence to solve a crime. Warm-up: Q22-30 DNA Detective Lab Activity DNA review - kahoot Closure - Q and A HW – DNA Quiz next class

Question 22 Approximately 18 DNA-bearing cells are needed to obtain an STR profile. A quantity of DNA that is below this level of detection is referred to as a low copy number.

1) all body fluids are considered to be infectious Question 23 An evidence collector should wear disposable latex gloves when handling biological evidence: 1) all body fluids are considered to be infectious 2) to reduce the possibility that the evidence collector will contaminate the evidence.

Question 24 Biological evidence should not be packaged in plastic or airtight containers because accumulation of residual moisture could contribute to the growth of DNA destroying bacteria and fungi. Articles containing biological evidence should be packaged separately in a paper bag or well ventilated box.

Question 25 Packages containing biological evidence should be refrigerated or stored in a cool location out of direct sunlight until delivered to the laboratory. One common exception is blood mixed with soil, which must be stored in a clean glass or plastic container and immediately frozen.

Question 26 The preservative EDTA should be added to blood samples collected from a crime scene. EDTA serves as a preservative and inhibits the activity of enzymes that degrade DNA.

Question 27 The least intrusive method for obtaining a DNA standard/reference is the buccal swab. In this procedure, cotton swabs are placed in the subject’s mouth and the inside of the check is vigorously swabbed, resulting in the transfer of cells from the inner cheek lining onto the swab.

Four ways to minimize contamination of biological evidence are: Question 28 Four ways to minimize contamination of biological evidence are: Change gloves before handling each new piece of evidence Collect a substrate control for possible subsequent laboratory examination Pick up small items of evidence such as cigarette butts and stamps with clean forceps Always package each item of evidence in its own well ventilated container

G-C-T-T-A-G-C-G-T-T-A-G-C-T-G-G-A-C Question 29 G-C-T-T-A-G-C-G-T-T-A-G-C-T-G-G-A-C

Question 30 You would first collect any blood or skin scraping’s from under the victim’s fingernails, because they might contain DNA. Then, extract the DNA and then amplify the DNA using PCR and separate the fragments using electrophoresis. Finally, you would look for the bands of separated DNA that corresponds to the amelogenin gene. If the sample contains two bands, the attacker is male; if sample contains only one band, the attacker is female.