Adapted from Flinn DNA Isolation



Test tube racks                                                95 % Denatured Ethanol

Test tubes with screw top lids                          Bathroom cups

Distilled Water                                               Drinking water

Dishwashing liquid                                            Salt


**Everyone will extract their own DNA


**Be sure to put on goggles and aprons

1.) Stations are set around the room with the salt solution, dishwashing liquid solution, and alcohol

2.) In your test tube, put about 20 drops of salt solution.  You can put your tube in the rack for a few minutes.

3.) Next, go to the water fountain and fill the bottom ¼ of your cup with water.

4.) Come back to the room and write your name on the cup.

5.) Put water in your mouth and swish; the more you swish, the more cells you will get

6.) Spit back into cup, no “loogies” you just want spit water

7.) Take a clean pipet and put about 4 mL of cheek water in your

            *With salt water and cheek water, your test tube will be about ½ full

8.) Next, add about 20 drops of dishwashing liquid solution.

9.) Screw the lid on tight and gently invert the test tube a few times. Do not shake it…if you see an abundance of bubbles you may have done too much

10.) Find the station with the alcohol. Look for the cooler. The alcohol is on ice and needs to stay there. There should also be a couple of 5 mL graduated cylinders at this station. Remember that alcohol is flammable and the vapors can be harmful. Be careful.

11.) Measure 5 mL of cold alcohol into the graduated cylinder. Add this to your test tube.

12.) Put your test tube in the rack and give it about 5 minutes

13.) If you do not have DNA, try and try again!

14.) When you are finished

            A. Rinse out test tubes thoroughly and put in the drying rack, be sure cap is put in proper place

            B. Clean up your table

            C. Pour remaining cheek water down the drain with water

            D. Throw cups away

            E. The material in the test tube can be put down the drain with water running

15.) Answer discussion QUESTIONS