CBST researchers are pioneering the use of laser trap Raman spectroscopy to identify and sort living stem cells from other non-stem cells in biological samples. Because this technique works without the need to break cells apart or use exogenous fluorescent labels (which can trigger cell activation or differentiation) -- it is ideally suited for current stem cell research applications.

Finding new ways to identify stem cells is one of the big challenges in this field. Some stem cells can be identified using unique surface receptors that can bind fluorescent labeled antibodies but these labels can modify the SC behavior. Some types of SC don’t have unique surface markers. The discovery of an alternate method of SC identification using Raman spectroscopy is expected to be an important breakthrough in this area. Raman spectroscopy is used to determine the biochemical content of the cell and indicates that the SC constituents are different from normal cells.

Raman spectra taken of human embryonic stem cells (hESC). From top to bottom: 
normal hESCs, hESC-cardiomyocytes (CMs), and fetal cell cardiomyocytes.

Cancer stem cells may also be distinguished from other cancer cells using this technique. Here, MCF-7 breast tumor cells are sorted from potential breast cancer stem cells (confirmed separately by CD surface marker analysis)

Classifying hESC, hESC-CM, and fetal CMRaman spectra using principal component + linear discriminant analysis.