This is actually very difficult to do. Mesenchymal stem cells have not been able to be isolated from the blood previously, even though they are probably there, because they are in such low quantities, and we don't know their phenotype in the blood. That's why many companies and investigators use bone marrow biopsies, fat tissue or dermal tissue to get mesenchymal stem-like cells. Its impressive if NBS scientists have been able to find these cells in human blood, as that will be an easily accessible source of these cells and relatively noninvasive.
I wonder if other scientists are going to go after NBS over this just like they did with the VSELs earlier this year, just because they can't find the exact cells that NBS can.