Measuring tiny volumes with precision and accuracy requires a micropipet. In the biology lab, micropipets are used for preparing and loading DNA samples, microscale experiments and the preparation of many types of samples. These applications rely on good technique to reduce error. This guide explains how to choose the proper micropipet for the application and techniques to help ensure that measurements are accurate and precise.
Hans Christian Oersted (1777–1851), a Danish physicist, was performing an experiment in 1820 when he noticed that whenever an electric current from a battery was switched on or off, a nearby compass needle was deflected. Through additional experiments, Oersted was able to demonstrate the link between electricity and magnetism. The following year, English scientist Michael Faraday (1791–1867) created a device that produced “electromagnetic rotation.” This device is known as a homopolar motor since the motor requires no commutator to reverse the current.
A motor converts electrical energy to mechanical energy. The simple motor in this activity changes the electrical energy output by the battery to mechanical energy as the copper wire is set into rotational motion. Any current-carrying wire produces an associated magnetic field. The electrons in the wire are subjected to a magnetic field and experience a force—referred to as the Lorentz force—that is perpendicular to both the magnetic field and the direction of movement. At some point along the length of the wire, the electrical current is not parallel to the magnetic field. The resulting Lorentz force is tangential and induces a torque on the copper wire. This torque causes the copper wire to spin.
Deoxyribonucleic acid (DNA) is the genetic material found inside the nucleus of eukaryotic organisms. The information coded by DNA determines the characteristics of an organism, including its size, shape and other unique features. How can this genetic material be isolated and identified? This activity describes one of the most common techniques used to examine DNA—electrophoresis. Continue reading
Here’s a twist on the classic chemical hand warmers you can buy for you to research and improve.
If you’ve been outdoors when it’s really cold, there’s a good chance you’ve either used these yourself or wished you had. You can experience a variation on the science found inside a commercial warmer with some pretty basic materials. You’ll discover how an everyday chemical reaction like rusting is used to keep your digits toasty. This experimental version of the hand warmer is offered as a test idea and not as a definitive solution. You’re encouraged to share your science fair results online.
Source: Homemade Hand Warmer | Science Experiments | Steve Spangler Science
By Jessica Miron.
Digging into Science: Let’s Talk Worms is comprised of a series of activities that invite grade 1 students to investigate the needs and characteristics of worms through research and hands-on science exploration. Continue reading
Contributed by: Derek Totten
…a good balance of science and fun!
- Simple machines help objects to move.
- Simple machines and mechanisms make life easier and/or more enjoyable for humans.
Curriculum Connection: Grade 3: Structures and Mechanisms Continue reading
Courtesy of Amanda Slater, Wikimedia Commons
««« By James Palcik
A solution is prepared containing a dye. The dye, methylene blue, is colourless in a reduced state. Upon shaking the solution, the dye is oxidized and displays a blue colour. As the solution stands undisturbed, the dye fades to colourless as it is reduced. The cycle may be repeated over and over.