Who ate the Cheese Forensic Science 12314 S

Who ate the Cheese? ? Forensic Science 12/3/14 S

Drill – Pd. 3, 5 S Put these steps for RFLP analysis in order. What is each step for? S Look at film and analyze S Use gel electrophoresis S Radioactive probes S Southern Blotting S Treat DNA with restriction enzymes S X-ray film S HW: Finish Paternity Testing or DNA in the Courtroom, if needed

Drill – Pd. 6 S Which man is the father? S 4 th page of packet, on the front S Answer questions S HW: S The Break-in (back of 4 th page) S Finish Paternity Testing or DNA in the Courtroom, if needed

Objectives S IWBAT S Analyze DNA to determine the most likely suspect. S Analyze a RFLP test.

Agenda S Drill S Who ate the Cheese? lab S Paternity Testing or DNA in the Courtroom S Closure

Who Ate The Cheese? S Oh no! Someone ate S How can we determine the Queen’s prize Limburger cheese! who ate the cheese? S Saliva samples were taken from the teeth marks left on the cheese

DNA Fingerprinting S A process which uses fragments of DNA to identify the unique genetic makeup of an individual. 1. PCR 2. Restriction Enzymes 3. Electrophoresis

PCR S Polymerase Chain Reaction S Replicates DNA sample S Produces millions of copies in 2 hours

Restriction Enzymes S Molecules that cut DNA segments into smaller pieces by breaking bonds S Cuts DNA into fragments of different lengths

Gel Electrophoresis S GEL ELECTROPHORESIS S DNA molecules have a negative charge. S The molecules migrate toward the positive pole. S The larger the molecule, the more difficult it is to make its way through the gel, so the shorter segments move farther than longer ones.

Who Ate the Cheese? S Work in pairs. Ms. Bloedorn will assign the pairs. S Each pair will get: S A description of the case scenario (Class set—don’t S S take!!) DNA sheet (you will cut this up) Analysis sheet (you will be turning this in) A sheet of printer or graph paper (your “gel”) A roll of tape—not enough for pairs, share with your table. S If not done at the end of class, put it in your folder until

Steps to Who Ate the Cheese? S Read the scenario and the directions. S One partner will prepare the “samples” (Steps 1&2) S One partner will prepare the “agarose gel” (Step 3) S Create the DNA “gel” together. S Create your finished “gel” and answer the questions on the back of the scenario paper. S Staple the “gel” and questions together. Turn in the final product.

Who Ate The Cheese? S After cutting out your fragments, count how many base pairs there are in each fragment. You may color-code the fragments, if you like (ex. Suspect 1 = blue, etc. ) S Lay it out horizontally, as Ms. Bloedorn demonstrates. Your range is 0 -31 bps. S You may end up with fragments overlapping on “lanes”. Just fold the fragments over before taping them down.

Choose a Case! S You get to decide: S Paternity Testing S DNA in the Courtroom S Hold onto this for discussion!

Closure S How many bands do you expect for each RFLP tested? Why? S Who discovered the structure of DNA? S Which proteins help unwind DNA during replication?