Show Me the Genes: Making Posters to Communicate Solutions
If an engineered biosensor bonds with a target strand of DNA, we can detect its presence by a shift in the interference pattern it produces.Copyright U.S. National Library of Medicine http://ghr.nlm.nih.gov/handbook/basics/dna
By this point in the unit, students have learned all the necessary information and conceptualized a design for how an optical biosensor could be used to detect a target strand of DNA associated with a cancer-causing gene as their solution to the unit's challenge question. Now student groups act as engineers again, using a poster format to communicate and prove the validity of the design. Successful posters include a description of refraction, explanations of refraction in a thin film, and the factors that can alter the interference pattern of a thin film. The posters culminate with an explanation of what is expected to be seen in a biosensing device of this type if it were coupled to a target molecule, proven with a specific example and illustrated with drawings and diagrams throughout. All the poster elements combine to prove the accuracy and viability of this method of gene detection. Together with its associated lesson, this activity functions as part of the summative assessment for this unit.
Many brilliant engineering designs are never realized or are delayed for decades, not because of error or unreliability of the design, but because they were not adequately disseminated to the larger production and consumer marketplace. If engineers are to succeed at designing successful products, they must be able to design the products AND successfully communicate their effectiveness and usefulness to companies and individuals who have the means of bringing them to manufacture and distribution. In this activity, students practice communicating ideas effectively by using a poster format to logically and cohesively present their solutions for gene detection in a way that people unfamiliar with the topic can be convinced of their value.
After this activity, students should be able to:
- Explain thin film refraction and the factors that influence it.
- Illustrate thin film refraction in an accurate diagram.
- Explain the experimental results of using an optical biosensor, and prove these results with a mathematical example.