Chromatin Isolation essays

Chromatin Isolation essays DNA is the blueprint for all living things. DNA is made of a material called chromatin. The purpose of this experiment was to attempt to isolate, or separate, chromatin from onion cells. My lab partner was Dave Sugg. Hypothesis: We should be able to isolate DNA from onion cells. Procedure: To begin, weigh out about 15 grams of onion cubes and place it in a 400 ml beaker. Add about 60 ml of homogenizing medium to the onion cubes. Place it in a warm water bath for 8 minutes. Dont let it tip over!!! This softens onion tissue and allows homogenizing medium to penetrate the onion. The enzymes also get denatured. Quickly cool the solution to 15-20 degrees Celsius in an ice bath. Dont let it tip over!! Put the cooled solution in a blender. Blend for 45 seconds at high speed. Pour the result into a 500 ml beaker. Put this into an ice bath for 8 minutes. Set up a filter (cheesecloth 2 layers) in a funnel during the 8 minute wait. Pour the white solution through the filter into the other 500 ml beaker (leave the foam behind!). Take 25 ml of filtrate and pour it into a clean 250 ml Erlenmeyer flask. Put the flask in an ice bath until it cools to 10 15 degrees Celsius. Slowly add 50 ml of ice cold ethanol down the side of the flask until a white, stringy chromatin pr ecipitate occurs (the stuff will look stringy and cloudy). Wind the stringy DNA on a glass rod by turning the rod in one direction only. Data: Before we poured the ice cold ethanol down the side of the flask in the final step, there was a film at the top of the solution. We poured in all 80 ml of ethanol. There were 3 clear layers; a clear ethanol layer at the top, a DNA interface, clear with whitish strands, and quite visible unlike the protein, and a yellow homogenate at the bottom. This experiment taught us the process of isolating DNA from onion cells. We learned a great deal from the completion of these extractions. We h ...