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Need protocols for DNA isolation from bird feathers - (Jul/31/2006 )

hi people,
need protocols for DNA isolation from bird feathers, please help if ne one has it...



I believe feathers are similar to hair in that they are protein structures that are produced, not cellular structures that grow, and therefore do not contain DNA. They may still have DNA in cells adhering to the ends of them (like from the root of a hair), or perhaps on them. If you attempt this perhaps you will only need the end the feather grows from.

Anyhow, extracting DNA from any tissue is not too hard... cut or chop it up (with clean sterile blade) and add it to a solution:

50mM Tris pH 8.0, 100mM NaCl, 5mM EDTA, 2mM CaCl2, 1% SDS, and 0.2-0.4 mM Proteinase K.

The proteinase K (an enzyme) will digest the protein in the sample, and the SDS (a detergent) will solubilize everything. It will be a very thick solution if you actually use feathers, so you should try to use a lot of the digestion solution.

Incubate with agitation at 55 C for 2-12 hours, then phenol/chloroform extract for DNA (to remove all protein), or do isopropanol/ethanol precipitation (not as clean as phenol/chlor but all DNA is retained). I have done this with cellular samples and get good DNA yield. After digestion, Per 500 ul of digestion solution, add 125 ul 7.5M ammonium acetate and 375 ul Isopropanol, mix gently. I have seen DNA at this stage as whispy white strings. Freeze if you really want to enhance precipitation. Spin at maximum 10 minutes (keep at 4 C if you really want to enhance precipitation), the DNA should be a white pellet, pour off solution, add as much 70% ethanol as your container will allow (to wash DNA and remove salt; I was adding 1.4 ml to a 1.5 ml tube), spin again, pour off solution, allow pellet to dry 10 minutes with lid open, resuspend in whatever volume water or TE you want.