Commercial supply stores have kits that they are happy to sell you for $100 + per class. There's an interesting one called, "genes in a bottle" where you extract your DNA and place it in a microcentrifuge tube tied to colourful thread which you can wear around your neck.
If you wanted to do this at home, there is "shot glass DNA extraction" those uses over-proof rum and other household materials. For the classroom, though, I found an excellent method at about.com: biology. Here’s the link:
http://biology.about.com/library/howto/htdnaextracthum.htm
The method is rated as simple and only takes 15 minutes. The materials are easy to find: small plastic cups (like a medicine cup for rinsing your mouth), small beakers, test tubes with stoppers, distilled water, salt, liquid dish detergent and rubbing alcohol (95% chilled alcohol could be used if that was more plentiful).
Other advantages to this method are that you don’t have to put in an order and wait for it.
If you want to take the extraction a step further so that students can proudly wear their DNA, it can be spooled into an Eppendorf tube which can be tied with colourful thread. These microcentrifuge tubes can be purchased for about $20 for a package of 500. That’s "Cents-ible Science"!
Saturday, November 22, 2008
Virtual DNA electrophoresis & make your own!
I am teaching gr. 12 Biology now and I have all kinds of fancy electrophoresis equipment. But that is not really necessary. Many university websites have lots of support for science activities. The University of Utah has a virtual tutorial where you learn to make and pour your own gels. It's fabulous and really reccommended for teachers and students alike. Here's the link:
http://learn.genetics.utah.edu/content/labs/gel/
If you want to make your own electrophoresis equipment with 5 x 9V batteries and a dish soap container attached to batteries with alligator clips, you could save yourself upwards of $2000!
Here's the link!
http://www.nexusresearchgroup.com/fun_science/electrophoresis.htm
http://learn.genetics.utah.edu/content/labs/gel/
If you want to make your own electrophoresis equipment with 5 x 9V batteries and a dish soap container attached to batteries with alligator clips, you could save yourself upwards of $2000!
Here's the link!
http://www.nexusresearchgroup.com/fun_science/electrophoresis.htm
Sunday, October 19, 2008
You Tube is the Biology Teacher's Best Friend!
Recently, my student teacher impressed me with some little videos that he incorporated into a Powerpoint presentation. I use PP also with little videos that we watch online - Virtual Cell Animation Collection being a real favourite of mine (watch the lac operon video - excellent!).This got me to thinking and surfing You Tube and I was amazed at the plethora of videos that are out there! BIO-RAD has a few videos, one of which is a spoof of "We are the World" but it's about PCR. It's so over the top and funny!Beyond that, there are so many that are really good with excellent graphics and interesting music. There is no way that I could reproduce any of it in 2 dimensions.
Thursday, July 24, 2008
Tie-Dye shirts with Sharpie Markers - no mess!
This is directly copy and pasted from the Steve Spangler website but I find that I really need to save this - it's a gem! I do paper chromatography with my students and have made beautiful patterns with the Sunday School kids for cards but this really is a good spin on an already cool lab activity!
Sharpie Pen Science A tie dye technique without the mess, using Sharpie Markers!
It's a brand new tie dye technique without the mess... and the results are amazing! This activity combines chemistry and art to create a designer t-shirt that is sure to get lots of attention whenever you wear it.
Materials
Pre-washed white t-shirt
Sharpie® Permanent Markers (Red, Orange, Yellow, Green, Blue, Purple)
Plastic Cup
Rubber Band
Rubbing Alcohol (70% from the Drug Store)
Dropper Bottle or medicine dropper
Link to see the video for the method: http://www.stevespanglerscience.com/experiment/00000032
Sharpie Pen Science A tie dye technique without the mess, using Sharpie Markers!
It's a brand new tie dye technique without the mess... and the results are amazing! This activity combines chemistry and art to create a designer t-shirt that is sure to get lots of attention whenever you wear it.
Materials
Pre-washed white t-shirt
Sharpie® Permanent Markers (Red, Orange, Yellow, Green, Blue, Purple)
Plastic Cup
Rubber Band
Rubbing Alcohol (70% from the Drug Store)
Dropper Bottle or medicine dropper
Link to see the video for the method: http://www.stevespanglerscience.com/experiment/00000032
Steve Spangler's Demo a Week E-mail
http://www,stevespanglerscience.com
I do not usually tout people's products but I recently visited the Steve Spangler website (http://www.stevespanglerscience.com/) and signed up to receive a weekly e-mail that features a different demo a week! It also shows a product that you can purchase but what can you expect?
This week's demo was the 7 layer density column, a colourful demonstration where you carefully pour different layers of liquids that settle into discrete layers due to their different densities. It is a demo that I already do, but he does it better. There are videos to show you how he does it and a full write up.
You can link to Steve's blog and it's really good for getting ideas! There are a lot of demonstrations shown of him on different TV shows and I have noticed that he doesn't always explain the science fully. One demonstration that I am keenly interested is the self-carving pumpkin (or watermelon). You carve the pumpkin from the inside, cut it to scoop out the content and make a hatch at the back so that you can insert materials to do the demonstration. Whatever reaction he does is explosive enough that it blows the eyes, nose and mouth out of the pumpkin! It is very cool! Now that I have heard about it, it's only a matter of time that I find out how!
I do not usually tout people's products but I recently visited the Steve Spangler website (http://www.stevespanglerscience.com/) and signed up to receive a weekly e-mail that features a different demo a week! It also shows a product that you can purchase but what can you expect?
This week's demo was the 7 layer density column, a colourful demonstration where you carefully pour different layers of liquids that settle into discrete layers due to their different densities. It is a demo that I already do, but he does it better. There are videos to show you how he does it and a full write up.
You can link to Steve's blog and it's really good for getting ideas! There are a lot of demonstrations shown of him on different TV shows and I have noticed that he doesn't always explain the science fully. One demonstration that I am keenly interested is the self-carving pumpkin (or watermelon). You carve the pumpkin from the inside, cut it to scoop out the content and make a hatch at the back so that you can insert materials to do the demonstration. Whatever reaction he does is explosive enough that it blows the eyes, nose and mouth out of the pumpkin! It is very cool! Now that I have heard about it, it's only a matter of time that I find out how!
Wednesday, July 9, 2008
Density Demo taken up a notch
I was helping out with our summer church camp and it was a science theme. They have a demonstration at the end of each day. The demo today really took my old diet Coke/regular Coke demo up a couple of notches.
First, put in a regular Coke, then a diet Coke. Ask for predictions from the audience each time about what they expect will sink or float and why.
Try:
Pepsi and Diet Pepsi
A lemon and a lime (the lime sinks, the lemon floats)
An peeled orange and an unpeeled orange (the orange floats, the peeled orange sinks)
And for a big finale, two bowling balls - one 7 lb and the other 16 lb (borrowed from a bowling alley). The 7 lb bowling ball floats and the 16 lb one floats!
And it's all about density and how tightly packed together those particles are. High density items (like people packed together on a bus during rush hour) that are more dense than water will sink. Low density items (like people in a bus during a slow time) will float!
First, put in a regular Coke, then a diet Coke. Ask for predictions from the audience each time about what they expect will sink or float and why.
Try:
Pepsi and Diet Pepsi
A lemon and a lime (the lime sinks, the lemon floats)
An peeled orange and an unpeeled orange (the orange floats, the peeled orange sinks)
And for a big finale, two bowling balls - one 7 lb and the other 16 lb (borrowed from a bowling alley). The 7 lb bowling ball floats and the 16 lb one floats!
And it's all about density and how tightly packed together those particles are. High density items (like people packed together on a bus during rush hour) that are more dense than water will sink. Low density items (like people in a bus during a slow time) will float!
Tuesday, July 1, 2008
Acid Rain Demonstration
Burningof sulphur – acid rain demonstration (Science & Society connection)
Apparatus: gas bottle, BTB indicator, glass plate, deflagrating spoon & sulphur.
Directions:
1. Fill gas bottle with water and add a few drops of BTB (indicator turns yellow in an acid or remains blue in basic or neutral solutions).
Put ½ tsp (amount is not critical) into the spoon and heat over the Bunsen burner flame. Ask a student to turn off the light so that the violet flame can be viewed.
Lower the spoon into the gas bottle, taking care not to touch the sides (see photograph). Cover with the glass plate. The white gas (SO2 and SO3) will billow and fill the air space above the blue liquid. Douse the flame in a waiting container of water (Safety alert – toxic gas produced is, use a fume hood).
Discuss with the class about societal and environmental implications of factories burning sulphur and the products that will come out of the smokestacks, like sulphur dioxide and trioxide. During this time, these two gases will dissolve into the water to form sulphurous and sulphuric acid, changing the pH from neutral to acid.
Cover the top of the bottle completely with the glass plate and shake once. The blue coloured solution will dramatically change to yellow. This indicates that the solution is now an acid. Explain how this demonstration shows how we get acid rain and the effects of air pollution on our lakes.
Extension: In Southern Ontario, there is a buffering effect of limestone (CaO) that will react with water to form calcium hyroxide (CaO + H2O--> Ca(OH)2). Since metal hydroxides are bases, this counteracts the effect of the acid rain. Therefore, Southern Ontario is not as affected by acid rain as it could be.
Apparatus: gas bottle, BTB indicator, glass plate, deflagrating spoon & sulphur.
Directions:
1. Fill gas bottle with water and add a few drops of BTB (indicator turns yellow in an acid or remains blue in basic or neutral solutions).
Put ½ tsp (amount is not critical) into the spoon and heat over the Bunsen burner flame. Ask a student to turn off the light so that the violet flame can be viewed.
Lower the spoon into the gas bottle, taking care not to touch the sides (see photograph). Cover with the glass plate. The white gas (SO2 and SO3) will billow and fill the air space above the blue liquid. Douse the flame in a waiting container of water (Safety alert – toxic gas produced is, use a fume hood).
Discuss with the class about societal and environmental implications of factories burning sulphur and the products that will come out of the smokestacks, like sulphur dioxide and trioxide. During this time, these two gases will dissolve into the water to form sulphurous and sulphuric acid, changing the pH from neutral to acid.
Cover the top of the bottle completely with the glass plate and shake once. The blue coloured solution will dramatically change to yellow. This indicates that the solution is now an acid. Explain how this demonstration shows how we get acid rain and the effects of air pollution on our lakes.
Extension: In Southern Ontario, there is a buffering effect of limestone (CaO) that will react with water to form calcium hyroxide (CaO + H2O--> Ca(OH)2). Since metal hydroxides are bases, this counteracts the effect of the acid rain. Therefore, Southern Ontario is not as affected by acid rain as it could be.
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