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
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.
|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.