Advanced optical imaging uncovers metabolic activity in blood immune cells

A new study published in *Biophotonics Discovery* demonstrates that advanced optical imaging can uncover the metabolic activity of individual peripheral blood mononuclear cells (PBMCs) in a routine blood sample. PBMCs—comprising lymphocytes and monocytes—are routinely analyzed with fluorescent antibodies that bind to surface markers, allowing researchers to identify cell types but offering limited insight into their functional state. The optical method described in the paper bypasses the need for fluorescent labeling, instead measuring intrinsic light signals that correlate with cellular metabolism.

Using a combination of label‑free multiphoton microscopy and spectroscopic analysis, the researchers were able to quantify metabolic markers such as NADH and FAD fluorescence in thousands of PBMCs simultaneously. This approach preserves the native cellular environment and provides a high‑throughput readout of metabolic heterogeneity, which is often linked to disease progression in infections, autoimmune disorders, and cancer. The technique also allows for rapid, non‑invasive monitoring of immune responses to therapies, potentially improving diagnostic precision and treatment monitoring.

The findings suggest that metabolic profiling of PBMCs could become a complementary tool to traditional surface‑marker assays, offering deeper functional insights without compromising cell integrity. As the method is scalable and compatible with standard laboratory equipment, it holds promise for broad clinical and research applications in immunology and personalized medicine.