http://www.freerepublic.com/focus/news/2133539/posts
Ivins kept the one-liter flask of RMR-1029, but some 300 people within the Institute also had access to the flask, according to those familiar with operations there. Before 1999, the preparation was stored in a separate containment area, about 100 yards from the main building. At that time, “access was more vague, because the flask wasn’t under Ivins’ direct custodial control,” Andrews says.
Ivins also shared samples of RMR-1029 with researchers at other facilities.
“Another lab might take a couple of milliliters of that spore preparation and create a daughter preparation,” Andrews says. “How many [samples] Ivins gave out I have no idea, but he did it through official channels, and there is a chain of custody records that indicates which labs got RMR-1029 and how much of the material they got.”
It was those “daughter preps” that ultimately led Fraser-Liggett to Ivins’ flask. Her team at the Institute for Genomic Research began DNA sequencing of the spores in the four anthrax-loaded letters recovered after the 2001 attacks. The team spent two years analyzing 20 different samples of B. anthracis to create a group of tests capable of genetically fingering the distinctive variety of anthrax found in the letters.
They screened nearly 1,000 samples of B. anthracis collected from labs around the world. “The results identified only eight samples that contained all four of the genetic mutations,” she says. “Each of those could be traced back to this one flask at USARMRIID-RMR-1029.”
“I have complete confidence in the accuracy of our data,” Fraser-Liggett says, but she concedes it fails to prove Ivins is guilty.