Search

This work presents the use of a Raman-based device and its integration/correlation with ultrasensitive microscopies (surface-enhanced Raman microscopy and confocal microscopy) for the molecular imaging and classification of normal lymphocytic B-cell and different leukemia cells from peripheral blood samples. The label-free Raman approach allowed for categorization of leukocytes into their respective lineage based on the biochemical information provided by Raman spectra. Furthermore, the single-point Raman analysis permitted the accurate discrimination of normal B-cells and leukemia-transformed cell lines (RS4;11, REH, MN60 cells), and more significantly, between leukemia cells in different differentiation/maturation stages. Raman imaging successfully and without cell destruction provided non-destructively information on the cell morphology, similarly to the standard May Grunwald-Giemsa histochemical staining protocol, but without the requirements for sample preparation. Finally, the specific analysis of the leukemic cell membrane by surface enhanced Raman scattering is shown. The reported results are promising for the development of a Raman-based protocol for the diagnosis and the complete morphofunctional assessment of cancer cells.

In this work, an approach based on digital holography (DH) combined with Raman spectroscopy (RS) is used for a complete label-free analysis of single bovine spermatozoa. DH allows to obtain high-resolution images of bovine sperm from the reconstruction of a single acquired hologram, highlighting in some cases morphological alterations. Quantitative 3D reconstructions of sperm head, both normal and anomalous, have been studied and an unexpected structure of the post-acrosomal region of the head has been detected. Raman imaging analysis have also confirmed such anomalies, suggesting the protein vibrations as associated Raman marker of the defect.

We report the generation of subdiffractive laser light focal spots in far-field regime, by means of the so-called Optical Eigenmodes (OEi) technique applied to the focusing properties of a single valve of Arachnoidiscus genus diatom. Diatoms are ubiquitous microalgae whose external walls are able to confine light in several hot-spots. We demonstrated that the presence of the valve brings a significant contribution to the OEi-induced light squeezing, improving its performance.