Posted: September 13th, 2017

Languages of Minds

Paper, Order, or Assignment Requirements

read the essay “mother tongue”, and write an essay follow the “writing topic”. please finish and develop my essay. follow my idea (thesis) to write the essay. you can change my first body paragraph, but make sure your idea is able to support my thesis. i am a Chinese student, plz write something like i am able to write. no grammar errors, and no professional knowledge.

 

2. DNA isolation

This is a crude DNA extraction that uses very familiar household chemicals and equipment. However, it demonstrates some key principles of molecular biology (you should comment on these in your report).

Safety: You must observe the usual laboratory safety precautions even though you are using familiar chemicals. The experiments are safe if carried out according to these instructions. Do not attempt to do experiments not described here.

 

What to do:

1. Add a heaped quarter teaspoon of salt and 100 ml of water to a beaker. Swirl the beaker to dissolve the salt. Add three-quarters of a teaspoon of washing up liquid and gently swirl to mix the contents. Place the beaker in the 60°C water bath.
2. Peel a kiwi fruit and chop it into small pieces. Scoop the pieces into the beaker with the water, salt and washing up liquid. Swirl the beaker to mix the contents.
3. Return the beaker to the water bath and leave for 15 minutes.
   [You could now prepare your gel for Part 2 of the experiment while you wait].
4. Pour the green mush from the beaker into a cafétière and use the plunger to push the solid material towards the bottom of the jug. Only push the filter about half way through the mush before pouring off the liquid into a champagne flute. You will need between one fifth and one quarter of a glass of liquid.
5. Very carefully run the ice-cold methylated spirits (or ethanol) down the inside of the champagne flute so that it forms a purple layer (or clear) on top of the green layer. When there is about 1/5th of a glass of methylated spirits, set the glass down and watch what happens at the interface between the two coloured layers. Describe this in your lab book.
6. It is sometimes possible to scoop the DNA out of the liquid by using a loop of wire, such as a paper clip.

3. Virtual DNA electrophoresis

Using a laptop, visit http://learn.genetics.utah.edu/content/labs/gel/ and follow the instructions.

 

Once you have finished the tutorial and understood the principles of DNA electrophoresis, return to your real gel and make observations.