Extracting DNA

[dttom]

I have tried to use the following method to precipitate out DNA, let's see if it is feasible.

I have prepared two small bottles of liquids/solutions, one is distilled water and another is my cheek cells in distilled water; on the other hand, I also have a bottle of concentrated sucrose solution. After mixing each liquids/solutions with the conc. sucrose solution, one with cheek cells have white precipitate seen while another does not. I doubt if those ppt. contain DNA or not. And if it is, mechanism could be like this. When cheek cells are exposed to distilled water, which is of zero water potential, higher than that in cheek cells, thus water migrates into cells by osmosis and finally leads to the burst of cells as well as nuclear envelope, hereafter, content in the cell would flow in the solution; after adding conc. sucrose solution, polynucleotides, including DNA as well as RNA, which is of relatively lower solubility, are expected to be salted out. Hence the white ppt., if the above description is correct, would contain DNA.

If there is anything wrong or loophole in the above description, please have them figured out and I'll be pleasant to hear.

I have pictured the result, and anyone who wants to take a look may have a gaze at it:

http://hk.pg.photos.yahoo.com/ph/loiyalunait/detail?.dir=/7c10scd&.dnm=caa5scd.jpg&.src=ph

[ecoli]

Generally, this method is done with saline solution rather than sucrose... I'm not sure how the sugar would affect the precipitation of DNA.

 

Another factor you can try is by heating the cells to varying temps, and see what temperature is best for DNA to come out of the cells.

[carol]

i think the cloudy part there are cellular debris, and you would still need to use eg. saline solution to precipitate the DNA and somehow separate it from the others.