Raman Spectral Signatures of Human Neutrophils: A Single-Cell Approach

<h4>Introduction</h4>With their noninvasive capabilities for molecular-level analysis of biological tissues and cells, Raman spectroscopy and microscopy have become important tools in medicine and medical diagnostics.<h4>Methods</h4>In this work, we describe a reliable and repeatable technique for Raman spectroscopic profiling of human neutrophils in peripheral blood smears. 1200 single-cell spectra from 12 healthy donors were obtained using Raman microscopy, and the results showed consistent spectral features of key biomolecules such as proteins, nucleic acids, carotenoids, and cytochrome c.<h4>Results</h4>We used t-distributed stochastic neighbor embedding and principal component analysis to assess interindividual variability; both techniques showed minimal spectral divergence between donors and high reproducibility. This study lays the methodological groundwork for upcoming Raman microscopy applications enabling non-invasive assessment of immune cell states in health and disease.<h4>Conclusion</h4>Our results demonstrate the potential of Raman microscopy in clinical diagnostics, specifically for tracking the metabolic states of cells.