In further experiments they showed that their technique works to detect the mixtures of immune cells associated with known diseases and that the technique works with blood exposed to storage conditions such as freezing and the addition of anticoagulants.
Moreover, in their experiments the team showed that to distinguish among and count those various immune cell types, they only needed to measure a few dozen methylation marks in the DNA. What's sufficient to constitute a signature, in other words, can be quite short.
The main ingredients of the method, Kelsey said, are libraries of methylation signatures of cells. Kelsey's lab determined the ones needed for this study, but big new epigenetics research consortia in Europe and the United States are poised to produce many more, greatly expanding the versatility of the proprietary method to cover more immune cells and other cell types as well.
In addition to the algorithms and the libraries, the test also requires some hardware, such as commercially available methylation microarrays.
The method has proven feasible enough that many other epidemiology research labs are already using it, Kelsey said. Brown University has also applied for a patent on the technique. He said it has the potential to be cheaper and faster than current techniques, although he didn't measure that in the paper.
|Contact: David Orenstein|