Lesson Title: Using DNA Hybridization to Explore Genetic Relationships
Author: Jason Falconio

This lesson is written in a 5 E's format: Engage, Explore, Explain, Extend, Evaluate.

ENGAGE

Materials: None

Time: 5-10 minutes

Activity:

	1.	With a partner, students brainstorm three things that they know about bacteria.
	2.	Partners share one item off of their list to make a class list of knowledge.
	3.	Teacher - from the list guide students thinking to medicine and research.

EXPLORE

Materials:

• Worksheet
  
  
• Article - A typing system for Neisseria gonorrheae based on Oligonucleotide probes to PIB Gene Variable Regions (PDF 336K)
  
  
• Article - Porin Variation among Clinical Isolates of Neisseria gonorrheae over a Ten-Year Period Determined by Por Variable Region Typing (PDF 527K)

Time: 15-20 minutes

Objective: SWBAT Analyze the main idea of this article by designing a graphic organizer.

Activity:

	1.	Have students read the abstract and introduction of the article. Ask students to underline or highlight words they are having trouble with.
	2.	Allow students to ask questions about the reading.
	3.	Students then work in pairs or groups to answer questions about the reading. As a class, clarify any misunderstandings here.
	4.	Extension- have students make a concept map representing the ideas found in the passage.

EXPLAIN

Materials: Power Point Presentation (3.8 Mb, PowerPoint required)

Time: 20-25 minutes

Objective: SWBAT describe why the Por gene should be researched and how the research is done.

Activity:

	1.	Students take notes on the reasons to study the gene, research done, and the method of hybridization.
	2.	In pairs, have students use paired verbal fluency to review the information. (Each student takes turns explaining something they learned while the other listens. They can switch every 30 sec.)

EXTEND

Materials:

• Hybridization photo (27K)
  
  
• Rulers
  
  
• Colored pencils or makers

Time: 30 minutes

Objective: SWBAT analyze the data provided and discover connections between the samples.

Teacher Notes:

	1.	How to read a blot: The sample side contains each sample of bacteria. The probe side contains the chemicals added to each bacterium to cause a luminescent chemical reaction.
	2.	The probes are grouped by loops on the protein that is produced by this gene. So each bacterium should have just one probe hit for each loop (1, 3, 5, 6, and 7).
	3.	This test is designed to look for similarities across individual samples. So two samples that have illuminated probes at the same spots on each of the 5 loops (1, 3, 5, 6, and 7), are genetically identical at those locations on the gene.
	4.	The students will be asked to look for similarities between samples to discover relationships.

Activity: (view Student Assignment)

	1.	Show students how to read a blot.
	2.	Using a ruler as a guide, students are to find the samples that have the same set of markings. The class can decide what counts as the same set of markings. For example: Sample e and g both have hits at 1-2, 3-1, 5-6, 6-5, and 7-3. They would color all the samples with this set a specific color. They can repeat this procedure until all matches have been found.
	3.	Have students continue to work together on the analysis section of this activity in groups.
	4.	In class discussion, be sure that the students understand possible applications of this method as it relates to the data seen.
	5.	In this discussion there are two remaining power point slides on limitations and drawbacks of hybridization: you can use these as notes or let students discover their own.
		*** You can add a short lesson on the importance of controls after this activity. The controls used on the table are the only ones scientists have genetic sequences for. So they are used as the part of the experiment with a known outcome.

EVALUATE

Materials: Large poster paper

Time: 15 minutes

Objective: SWBAT demonstrate their understanding of DNA hybridization.

Activity:

	1.	Have students in groups of four; design a graphic organizer titled DNA hybridization.
	2.	There are four sections the group must explain: description of hybridization, applications of hybridization, information on Gonorrhea, and the benefits and drawbacks of hybridization.
	3.	Students can present these graphic organizers for a grade or use to study for an essay or quiz grade.

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