The following DNA extraction protocol should be referenced as: Bush, K.L. 2007. DNA extraction technique for plucked historic feathers using the QIAamp® DNA Micro Kit. Last modified August 15, 2007. http://www.aviangenetics/DNA_extraction_index.htm
QIAamp® DNA Micro Kit - Isolation of Genomic DNA from Tissue Samples
(Qiagen (2003) QIAamp® DNA Micro Handbook. Protocol for isolation of genomic DNA from tissues, pp. 35-37. QIAGEN (Valencia, California, U.S.A.).
Protocol for Plucked Historic Feathers
(1) Cut the tips of 5 plucked feather samples into small pieces (~1mm) into a labeled 1.5ml microcentrifuge tube with sterile fine tipped scissors. Use 100% ethanol and DNA Away® to clean scissors in between samples.
(2) Add 200µl of Buffer ATL to each sample.
(3) Add 20µL of Proteinase K to each sample and vortex for 30 seconds.
(4) Incubate at 50˚C for 48-72 hours. Extended incubations can lead to more effective lysis of the DNA containing cells and a higher end product DNA concentration.
(5) Add 2µl of carrier RNA dissolved in Buffer AE to every 200µl of Buffer AL to be used in the extraction process. Add 200µl of the Buffer AL/carrier RNA mix to each sample and vortex for 30 seconds. Incubate the samples at 70˚C for 10 minutes.
(6) Add 200µl of cold 100% ethanol and vortex for 20 seconds.
(7) Incubate the samples at room temperature for 5 minutes.
(8) Transfer the solution from the microcentrifuge tube to a labeled spin column and centrifuge at 10,000 x gravity for 1 minute. Discard the tube containing the flow through.
(9) Add 500µl of Buffer AW1 to each sample and centrifuge at 10,000 x gravity for 1 minute. Discard the tube containing the flow through.
(10) Add 500µl of Buffer AW2 to each sample and centrifuge at 10,000 x gravity for 1 minute. Discard the tube containing the flow through.
(11) Put each spin column in a new collection tube and centrifuge at 14,000 x gravity for 3 minutes.
(12) Put the spin column into a labeled microcentrifuge tube and add 110µl of Buffer AE.
(13) Incubate the samples at room temperature for 5 minutes.
(14) Centrifuge at 7,000 x gravity for 1 minute and discard the spin columns. Freeze the extracted DNA samples at -20˚C for future use. DNA extracted from any kind of feather produces low quality DNA and 5-10µL of DNA is required per 15µL PCR reaction. If you have more than 5 feathers from the same individual, save the spin column to extract the second set of DNA (I have used spin columns to successfully extract 4 rounds of DNA from individual samples).