Method of isolating stem cells

Patent Number: 6991897

This and patent #5,876,956 are licensed to the company Aldagen (2810 Meridian Parkway Suite 148 Durham, NC 27713 919-484-2571) that is actually purifying stem cells using this method for clinical trials (for example: Intramyocardial Injection of Autologous Aldehyde Dehydrogenase-Bright Stem Cells for Therapeutic Angiogenesis at Texas Heart: Oct 5, 2006). The patent covers purifying stem cells based on expression of the enzyme aldehyde dehydrogenase . The patent has three independent claims, the first covering a method of detecting stem cells, the second a method of detecting cells from a population, and the third a method of isolating stem cells. All independent claims use expression of aldehyde dehydrogenase, and its activity as assessed by degradation of the substrate BODIPY aminoacetaldehyde (BAAA) as a method of obtaining the cells. This is a very interesting situation from a patent perspective since it is known, at least in cord blood that in a population of stem cells exressing aldehyde dehydrogenase, at least some express the marker CD34 (Storms RW et al. Distinct hematopoietic progenitor compartments are delineated by the expression of aldehyde dehydrogenase and CD34.Blood. 2005 Jul 1;106(1):95-102). Now patent 5,061,620 claims a hematopoietic cell population that is Thy-1 positive and CD34+. Therefore it will be interesting to see if the 5,061,620 patent is used as prior art against people using the current patent since there is a possibility that the current patent purifies, at least to some extent, a similar cell as claimed in this patent.

View this patent on the USPTO website.