Biology
May 17, 2019
SWBAT – extract DNA from their own bodies
EQ- How can we extract DNA without destroying the DNA itself?
Do now- In groups, students will remember the structure of a cell and list the structures that are between the outside and the DNA of a cell.
(Image of strings and clumps of DNA)
That's your DNA!
Questions-
What can I do to increase my yield of DNA?
At an extraction of DNA from a silica-dried plant leaves (50-60 mg), using a buffer consists of CTAB 2%, boric acid, Tris, EDTA, NaCl, Urea, and PVP, I got a small size pellet with low yield of DNA. I add 1 % Mercaptoethanol to the buffer at the time of the extraction and precipitate organic and non-organic substances with Phenol: Choroform-Isoamyl (25:24:1)for one time and with Choroform-Isoamyl (24:1) for two times. My plant is rich in polysaccharides which precipitated in the last supernatant with Ammonium Acetate. I would like to know, under these conditions, how can I increase the yield of DNA?
Why add salt? What is its purpose?
Salt is like the particales, we put it in are mouth and now the salt has are dna in it
Why is cold water better than warm water for extracting DNA?
Warm water can make the salt melt or go away because its hot, but with cold water it will stay there
Why does the DNA clump together?
When molecules are insoluble (unable to be dissolved), they clump together and become visible. DNA is not soluble in alcohol; therefore,...
