| AVS 59th Annual International Symposium and Exhibition | |
| Biointerphases Focus Topic: Bioimaging | Wednesday Sessions |
| Session BN+AS-WeA |
| Session: | Bioimaging |
| Presenter: | I. Notingher, University of Nottingham, UK |
| Correspondent: | Click to Email |
However, the current conditions to derive specific cell types remain suboptimal, generally producing only low yields of the desired differentiated lineages within highly heterogeneous populations that are not suitable for clinical use due to the presence of mainly unwanted cell types. This current limitation in the delivery of validated stem cells suitable for clinical applications, highlights the immediate need for non-invasive techniques capable of phenotypic identification of live cells within highly heterogeneous populations.
Raman micro-spectroscopy (RMS) is a label-free technique which can be used for imaging of live cells. This technique combines the high chemical specificity of Raman spectroscopy with the high spatial resolution of optical microscopy to provide detailed molecular information of complex biological samples. Since RMS has only a minimal background signal from water, it allows repeated observations of viable cells maintained under physiological conditions, which is difficult by other molecular vibrational techniques.
In the first part we will focus on using RMS to detect molecular markers for individual live cardimyocytes (CMs) derived from human embryonic stem cells (hESCs). The ability to monitor and quantify these spectral markers during differentiation periods as long as 5 days is also demonstrated. The analysis of Raman spectra of hESC-derived CMs were characterised by increased signals associated to myofibrils and glycogen compared to the other differentiated cells present in the cultures. The prospects of label-free Raman activated cell sorting are also discussed.
The second part will present results on using RMS for imaging and quantifying spectral markers in neuronal stem cells (NSCs). Raman spectra of undifferentiated NSCs are compared to those of glial cells derived from NSCs, with the aim to identify molecular markers which can be used for assessing the differentiation status of the NSCs. High resolution spectral maps corresponding to nucleic acids show that NSCs are characterized by increased concentrations of cytoplasmic RNA.
These studies demonstrate that RMS represents a feasible approach for label-free non-invasive characterization of individual live cells and can be used to assess the differentiation status and the phenotypes of individual cells.