The fact is hair is very resilient. You can clean any suggestion of contamination from the surface of the hair without damaging the DNA that lies within. This is something we have only known in the past couple of years.Below is an excerpt from the Ketchum DNA Study Supplemental Data - Material and Methods
DNA Isolation
Since the presence of normal human DNA contamination of submitted samples was a primary concern throughout this study, all samples were thoroughly cleaned in a manner consistent with forensic testing procedures. In order to further rule out contamination from human personnel and lab workers, samples from submitters and scientists working with the samples were collected for comparison with the results obtained in the various DNA tests.
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| Hair Sample I Forensically Collected for the Ketchum DNA Study |
Hair samples were then sorted into two groups for extraction at DNA Diagnostics. DNA from those samples containing 5-50 or more single hair roots were selected and the roots clipped into 1.5 mL microcentrifuge tubes. The hair roots were thoroughly cleansed with water and ethanol prior to extraction to remove any extraneous DNA.
Hair roots were placed in microcentrifuge tubes for DNA extraction and ATL buffer (Qiagen) was added. These samples were digested with proteinase K (PK, 20 mg/mL) and dithiothreitol (DTT, 1.0 M) at 56°C overnight, followed by a three-step organic extraction procedure using phenol:chloroform:isoamyl alcohol (25:24:1) with an additional PCI extraction. This process was followed by a butanol wash and buffer exchange/concentration into TE-4 buffer (10 mM Tris, 0.1mM EDTA, pH 8.0) using Microcon®-100 ultrafiltration devices (Millipore, Billerica, MA)93-94.
It appears that Dr. Sykes is not the "friend" that the critics and skeptics of the Ketchum DNA Study hoped he would be.
Ya know, while all of this is very interesting, I still find it ironic that
ReplyDeletethat smallest particles know to man are used as evidence to verify
the existance of an 800 lb. creature. We readily accept the results
of The Hubble Telescope floating around in space sending back pictures of stuff millions of miles away and yet we question what we
see in our own back yard. Maybe DNA tests will someday explain
that.
Is the hair sample pictured the one you collected or Dr. Sykes collected?
ReplyDeleteThat one is mine for the Ketchum DNA Study, I noted so in the caption
DeleteThank you. I saw the "I" but wasn't sure if it was referring to Sykes since the article was about him. Thought maybe you were posting a picture he had posted...I am easily confused. : ?
DeleteWell this is a pleasant surprise!! Glad to see this,for sure.
ReplyDeleteOk, and the results were still that the DNA from the hair was human.
ReplyDeleteOk, and the results were still that the DNA from the hair was human.
ReplyDelete