MULTIFACETED MICROARRAYS: Researchers studying induced pluripotent stem cells are turning to microarrays to verify the genomic stability of their cells.© SAM OGDEN/SCIENCE SOURCEAs it becomes easier and easier for scientists to generate induced pluripotent stem cells (iPSCs) in the lab, validating and monitoring those cell lines will become a routine—but critical—business. The usefulness of iPSC lines for basic research and therapeutic applications lies in the stem cells’ ability to maintain an undifferentiated state; but a small fraction of iPSCs spontaneously differentiate as they’re passaged. Scientists using iPSC lines for regenerative medicine require that high genetic integrity be maintained uniformly through many cell passages. Thus, researchers have to validate and monitor any new cell line at its discovery and throughout its life in the lab—and microarrays are rising to the task.
“We’re trying to anticipate the needs of the stem cell and the iPSC community,” says Seth Taapken, cytogenetics client services manager at Madison, Wisconsin–based WiCell Research Institute, a research nonprofit previously home to the National Institute of Health’s National Stem Cell Bank. “And they’re going to need a lower-cost but very effective screen for changes,” in stem cells, he says. Currently, researchers can use sequencing, the older technique of karyotyping—a visual evaluation of the number and physical characteristics of chromosomes—or a hodgepodge of arrays to evaluate the stem cells’ genomes. But there are no standard methods, and streamlined monitoring procedures for pluripotency and differentiation are still being developed. Moreover, there are currently no accrediting or professional groups that set mandates or standards for iPSC verification.
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