The purpose of this article is to help teachers integrate biotechnology into their classroom, by providing resources along with background information and a guide to appropriate topics and exercises. Should biotechnology topics be included in the Biology classroom? My answer is a resounding “Yes!” because biotechnology
A strip of eight PCR tubes, each containing a 100?l reaction. The PCR is a technique widely used in molecular biology. Source: Wikimedia Commons.
Studying biotechnology can inspire students to study biology.
To understand issues, students must learn the science behind the issues.
can provide a “hook” for getting students interested in and excited about biology, since this topic is frequently featured in the news media
illustrates the integration of basic scientific research into applied biology; for example, basic research about the biology of viruses that infect bacteria led to the modification of viral DNA to act as a vehicle for moving specific genes from one cell to another
underlies many current social and ethical controversies
encompasses methods that are widely used in all areas of biology, and students with an interest in biological research should be exposed to these techniques early in their training
Many teachers are reluctant to teach about biotechnology.
In spite of the importance of biotechnology in modern biological science, many teachers are reluctant to include concepts about biotechnology in their classrooms because they are concerned that biotechnology
Resources for teaching biotech are readily available.
- may be too complex for students
- may be too expensive to implement
- is not within the teacher’s area of expertise
- may be too controversial to manage in the classroom
However, many resources are available to help teachers incorporate laboratory and other biotechnology activities in the classroom, to provide background, and to facilitate discussions about controversial topics.
Learning about DNA is a good starting point for students.
Biotechnology techniques and background
Modern biotechnology methods rely on the isolation and subsequent manipulation of DNA. Once students are familiar with DNA and its role in genetics, a useful starting point for introducing biotechnology concepts is DNA isolation.
Although DNA isolation techniques vary slightly depending on the experimental organism, all of these techniques share the following characteristics:
- a treatment for breaking open cells and releasing DNA
- a method for removing or inactivating DNA-degrading enzymes
- a means of separating DNA from proteins and other contaminating molecules
Isolating DNA from bacteria is a good lab exercise.
There are several simple, inexpensive laboratory exercises for DNA isolation from bacteria, onions, and other organisms. They generally use heat and detergent to break open cells and inactivate DNA-degrading enzymes, and separate DNA from most other contaminants using precipitation with alcohol. There are many published methods for simple DNA isolation. The method I have found to be most reproducible is DNA isolation from bacteria16, although there are a number of published isolation exercises using onions9,10,12,16 and other organisms and tissues. Many biological supply companies sell kits for this technique and others.
Another technique at the heart of many biotechnology methods, called DNA transformation, involves adding foreign DNA to cells. This foreign DNA then can be “turned on” to make a useful product. This method has been used to produce many pharmaceuticals, such as human insulin.
Bacteria can also be used for DNA transformation.
For classroom purposes, DNA transformation is most easily accomplished in bacteria. The basic scheme is to
- take a bacterial mini-chromosome called a plasmid,
- insert foreign DNA into the plasmid,
- and then put the modified plasmid back into bacteria.
Many transformation laboratory exercises have been published.4,15,16 Some companies sell pre-packaged DNA transformation kits.
Restriction enzyme digestion and analysis
Restriction enzymes are proteins that cut DNA molecules at specific sequences of bases. These enzymes allow biotechnologists to reproducibly cut DNA molecules into well-defined fragments. Restriction enzymes are frequently used in biotechnology to analyze and make new DNA molecules.
Typically, the analysis of DNA using restriction enzymes involves a technique called agarose gel electrophoresis.
- Agarose consists of chains of sugars, and has a consistency similar to gelatin when used for this purpose.
- An electric current moves the DNA through the agarose, and the DNA molecules separate according to their size, with the smaller DNA molecules moving faster.
- The bands of different-sized DNAs are then detected by means of a dye added to the gel.
Different-sized DNA bands can be analyzed in a school lab.
One of the easiest ways to incorporate these techniques in the classroom is to do a combined restriction enzyme digestion & agarose gel electrophoresis laboratory exercise. Typically, students would do a restriction enzyme digestion on an inexpensive, readily available DNA, then run that DNA in an agarose gel. Students would then analyze the pattern of different-sized DNA bands.
A number of articles describe laboratory activities that deal with this topic.14,16,17,21 In addition, all the companies listed in the previous two sections sell pre-packaged kits that demonstrate these techniques. If your budget does not allow conducting wet labs, a number of simulation activities have also been developed.16,24,26,29,30
Polymerase Chain Reaction
The PCR (Polymerase Chain Reaction) has become a common biotechnology technique for the production of multiple copies of relatively short DNA molecules. This method is somewhat analogous to a molecular copy machine for pages (short sections) of DNA. PCR requires
- DNA that will act as a template
- short, single-stranded DNAs called primers (starting points for making DNA)
- an enzyme that makes DNA
- the building blocks of DNA called nucleotides
- a machine called a thermal cycler, which repeatedly subjects the reaction mixture to varying temperatures
Polymerase Chain Reaction can be demonstrated in the lab or by computer simulation.
There are a number of ways to incorporate PCR into the classroom. Simulations of PCR can enhance student understanding of the methodology without the need for equipment and supplies.8,16 Basic equipment, such as two or three water baths, can be used to perform the reactions if a thermal cycler is not available. For advanced classes, several exercises using a thermal cycler could be included.5,11,25 There are commercial pre-packaged kits for doing PCR in the classroom.
DNA sequencing is the heart of the human genome project, and is indispensable for many biotechnology projects. The purpose of DNA sequencing is to determine the exact order of bases (letters) in a DNA molecule. This information can then inform a scientist about the nature of a protein encoded by that DNA, the likely evolutionary relationship between different organisms, and a wealth of other information.
There are many avenues for incorporating DNA sequencing into the classroom. These include
DNA sequencing, key to many biotech projects, can be incorporated into class lessons.
- simulations done with pencil and paper16,18
- downloading and analyzing real sequence data over the internet19,22,23,27
- having students prepare DNA (e.g., through PCR, as described above), sending out the DNA for sequencing, and then analyzing the sequence data13
One of the best places for information about the last option is the Dolan DNA Learning Center site.11 They have developed a kit for doing PCR from students’ DNA (available through Carolina Biological Supply Company) and, currently, they will sequence that specific DNA for free.
Students can view microarray data and internet-based simulations of this technique for gene analysis.
Until recently, when it came to answering questions like “Which genes are expressed in cancer cells that aren’t expressed in normal cells?,” a very laborious gene-by-gene analysis was required. Techniques using microarrays are now available for simultaneously analyzing the expression of many genes. These microarrays are made on either a glass slide or silicon chip, and contain hundreds or thousands of parts of genes in a small section of the slide or chip. In this procedure, the expressed genes are isolated from cells, after which those genes are detected by determining which DNAs on the chip bind to which genes from the cells.
Wet lab exercises are difficult with this technology, since it is quite new and the supplies and equipment are expensive. However, students can experience microarrays in several ways, including viewing examples of microarray data6 or viewing an internet-based simulation describing how gene expression is studied using microarrays7. Many companies that manufacture microarrays have information for educators on their websites.1
Social and ethical issues relating to biotechnology
Discussion of biotech controversy requires fact-based understanding of issues.
Biotechnology applications have generated many social and ethical controversies. In a biology classroom, I think the best approach is to help students understand the information behind developments in biotechnology so they can develop a fact-based understanding of the potential benefits and risks associated with these techniques.
Some examples of biotechnology-based controversies include:
- genetically modified foods
- genetically engineering microbes for bioremediation
- cloning whole organisms
- embryonic stem cell research
- gene therapy
- genetic testing
Conclusion: Biotechnology belongs in the biology curriculum because of its importance in today’s world.
Background information on many of these controversies, and some excellent suggestions for dealing with these issues in the classroom, is found in a number of references.2,16,20,28
Many resources are available to help teachers incorporate biotechnology lessons into their classes. The information that could be included ranges from simple to complex, from purely scientific issues to ethical issues, from lecture to dry lab to extensive wet lab activities. Because of its currency and importance in modern biology, teachers should strongly consider adding biotechnology topics to their curriculum.
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Biotechnology Topics in the Biology Curriculum
A compendium of articles, exercises, current bioscience news, and other information, designed primarily for biology teachers. The second link leads to DNA extraction activities for the classroom.
Bioethics.net, produced by the Center for Bioethics at the University of Pennsylvania, is the Internet’s first and “most read source of information about bioethics.”
Dolan DNA Learning Center
Housed at the Cold Spring Harbor Laboratory, this site has a wealth of resources for students and teachers interested in biotechnology. The second link takes you to their related site “Unwinding DNA.”
Learn about biotechnology online
“Guide to Biotechnology” from the Biotechnology Industry Organization provides an overview about biotechnology. No science background is required. Chapters cover history, technologies and their applications, and ethics.
Genetic Science Learning Center
Housed at the Eccles Institute of Human Genetics, this site provides information about genetics, genetic testing, and related issues for the general public and educators.
Electronic Journal of Biotechnology
A wealth of resources about biotechnology, including an extensive links list of biotechnology organizations and online resources.
Genetics and genetic engineering glossary
Contains an extensive list of definitions related to biotechnology.
Facets of biotechnology explained, e.g., genome mapping, pharmacogenomics, and bioinformatics, from the US National Center of Biotechnology Information.
National Center for Biotechnology Information
Sponsored by the National Institutes of Health, this site has access to journal abstracts via PubMed, detailed information about human genetic diseases through the OMIM database, and access to a variety of DNA sequence databases.
Truth about Trade & Technology
News reports, press releases, an annual global farmer roundtable, and publications from around the world highlight a variety of biotechnology issues. Read their blog or editorials and learn what farmers from other countries are thinking and doing about biotech crops in their regions.
Greenpeace on genetic engineering
A site that describes concerns about some aspects of biotechnology and provides suggestions for involvement.
Teaching Resources from the Northwest Association for Biomedical Research (NWABR)
The Northwest Association for Biomedical Research (NWABR) strengthens public trust in research through education and dialogue. Its diverse membership spans academic, industry, non-profit research institutes, health care, and voluntary health organizations. Through membership and extensive education programs, it fosters a shared commitment to the ethical conduct of research and ensures the vitality of the life sciences community.
Advanced Bioinformatics: Genetic Research
This curriculum unit explores how bioinformatics is used to perform genetic research. Students examine DNA sequences from different animal species, investigate the relationship between protein structure and function, and explore evolutionary relationships among eukaryotic organisms. Throughout the unit, students are presented with a number of career options in which the tools of bioinformatics are developed or used.
Stem Cell Research
This unit, which was designed by teachers in conjunction with scientists, ethicists, and curriculum developers, explores the scientific and ethical issues involved in stem cell research. While exploring the ethics of stem cell research, students will develop an awareness of the many shades of gray that exist among positions of stakeholders in the debate.
NWABR Research Study on Bioethics Education
Fostering Critical Thinking, Reasoning, and Argumentation Skills through Bioethics Education ¨Cresults show that when students learn strategies for ethical reasoning, they grow significantly in their ability to develop strong arguments for their positions.
Biotechnology Education Teacher Resources
Find biotechnology education information and teacher resources, including a biotechnology timeline and careers in biotechnology.
nhà cái tặng tiền cược miễn phí thánghttp://www.biotechinstitute.org/resources/index.html
Long list of downloadable handouts, lessons, posters and other educational materials.
- Affymetrix. Educator’s Resources.
http://www.affymetrix.com/corporate/outreach/educator.affx (accessed August 1, 2002) March 9, 2010 No longer available.
- Anderson, R. 1998. “Collaborative learning in biology. Debating the ethics of recombinant DNA technology.” Am. Biol. Teacher 60:202-205.
- The Biology Project: DNA Isolation from Plant Tissue.
http://biology.arizona.edu/sciconn/lessons2/Alongi/lesson3.html (accessed August 1, 2002)
- Bloom, M., G. Freyer, & D. Micklos. 1995. Laboratory DNA Science. Benjamin Cummings, Menlo Park, CA.
- Brandner, D. 2002. “Detection of genetically-modified food.” Am. Biol. Teacher 64:433-442.
- Brown, P. 2001. Array Scans. http://cmgm.stanford.edu/pbrown/explore/tup1.jpg (accessed August 1, 2002) and http://cmgm.stanford.edu/pbrown/explore/yap1.jpg (accessed August 1, 2002) (links no longer available).
- Campbell, A.M. 2001. DNA Microarray Methodology - Flash Animation. http://www.bio.davidson.edu/courses/genomics/chip/chip.html (accessed August 1, 2002)
- Campbell, A.M., J. Williamson, D. Padula, and S. Sundby 1997. “Use PCR and a single hair to produce a ‘DNA Fingerprint’.” Am. Biol. Teacher 59 172-178.
- Carolina Biological Supply Company. Onion DNA Extraction. http://www.carolina.com/biotech/onion.asp (accessed August 1, 2002, no longer available online)
- DeBoer, L., R. Sobieski, and S. Crupper. 2000. “Isolation and restriction endonuclease digestion of onion DNA in the junior college-high school biology laboratory.” Bioscene 26(3):15-17.
- Dolan DNA Learning Center. Genetic Origins. http://www.geneticorigins.org/geneticorigins/ (accessed August 1, 2002)
- Dollard, K. 1994. DNA Isolation from Onion. http://www.accessexcellence.org/AE/AEC/AEF/1994/dollard_onionDNA.html (accessed August 1, 2002)
- Galewsky, S. 2000. “Sequencing cDNAs: AniIntroduction to DNA sequence analysis in the undergraduate molecular genetics course”. Bioscene 26(4):23-25.
- Guilfoile, P. and S. Plum. 1998. “An authentic RFLP lab for high school or college biology students.” Am. Biol. Teacher 60:448-452.
- Guilfoile, P. and S. Plum. 2000. “The relationship between phenotype & genotype. A DNA transformation & DNA isolation laboratory exercise.” Am. Biol. Teacher 62:288-291.
- Kreuzer, H. and A. Massey. 2001. Recombinant DNA and Biotechnology. A Guide for Teachers. 2nd Ed. ASM Press. Washington, DC.
- LaBanca, F. and C. Berg. 1998. “A time-efficient & user-friendly method for plasmid DNA restriction analysis.” Am. Biol. Teacher 62:453-456.
- Latourelle, S. and B. Seidel-Rogol. 1998. “A demonstration of automated DNA sequencing.” Am. Biol. Teacher 60:206-211.
- Maier, C. 2001. “Building phylogenetic trees from DNA sequence data: Investigating polar bear & giant panda ancestry.” Am. Biol. Teacher 63:642-646.
- Nardone, R. 1997. “Hello Dolly! And thanks for the opportunity you provided.” Am. Biol. Teacher 59:260-262.
- Palladino, M., and Emily Cosentino. 2001. “A DNA fingerprinting simulation laboratory for biology students.” Am. Biol. Teacher 63:596-603.
- Palladino, M. 2002. “Learning about the Human Genome Project via the Web: Internet resources for biology students.” Am. Biol. Teacher 64:110-116.
- Putterbaugh, M., J.G. Burleigh. 2001. “Investigating evolutionary questions using online molecular databases.” Am. Biol. Teacher 63:422-431.
- Reed, E. 2001. “A DNA fingerprint simulation: Different, simple, effective.” Am. Biol. Teacher 63:437-441.
- Roth, W.B., M. Thompson, R. Hallick. 1997. “DNA fingerprinting in a high school research-based science course.” Am. Biol. Teacher 59:48-51.
- Schug, T. 1998. “Teaching DNA fingerprinting using a hands-on simulation.” Am. Biol. Teacher 60:38-41.
- Smith, T. and D. Emmeluth. 2002. “Introducing bioinformatics into the biology curriculum: Exploring the National Center for Biotechnology Information.” Am. Biol. Teacher 64:93-99.
- Taras, L., A. Stavroulakis, M. Ortiz. 1999. “Human cloning: Lets discuss it.” Am. Biol. Teacher 61:341-344.
- Thompson, J., S. Gray, J. Hellack . 1997. “Linguini models of molecular genetic mapping & fingerprinting.” Am. Biol. Teacher 59:416-418.
- Wagner, J. 1998. “Recombinant DNA paper model simulation.” Am. Biol. Teacher 60:531-534.
Agarose gel electrophoresis - A technique for separating DNA molecules, based on the size.
Biotechnology - Human modification of organisms to produce a useful product. Over the past 20 years, the range of possible modifications has dramatically increased with the development of genetic engineering methods.
Bioremediation - The use of organisms to clean up polluted sites.
DNA sequencing - A technique for determining the exact order of nucleotides in a DNA molecule. This information is often useful in determining the likely function of that DNA molecule.
Enzyme - A protein that speeds up the rate of a chemical reaction.
Gene - A portion of a DNA molecule that encodes a function. That function is typically determined by the protein encoded by a particular gene.
Microarrays - A technique for determining which genes are expressed in a given cell or tissue. The microarray itself is a glass slide or silicon chip containing hundreds of tiny spots, each spot containing a different DNA sequence from a different gene.
Nucleotides - The basic building blocks of DNA. There are 4 different nucleotides (A, C, G, T) and the order of these 4 nucleotides determines the role a given DNA plays in a cell.
Plasmid - A small, circular DNA molecule that acts like a miniature chromosome that is often used for the insertion of foreign DNA.
Polymerase Chain Reaction - A technique for massively and rapidly amplifying a specific, short DNA molecule.
Primers - Short, single-stranded DNAs that are used in DNA sequencing, Polymerase Chain Reaction, and many other biotechnology techniques. As the name suggests, primers are the initiation point for these reactions.
Restriction enzyme - A bacterial protein that cuts DNA at specific sequences. Hundreds of different restriction enzymes have been discovered so far.
Transformation - A technique for introducing DNA into a cell.