Figure 8.

Flow cytometry (FC): instrument, measuring principle, and final outcome. (A) Schematic illustration of the measurement principle of a flow cytometry instrument. The particle suspension is injected into a flow cell. On the outer side a sheath fluid is applied and results into a hydrodynamic focusing. After this focusing the suspension enters a narrow capillary. At a fixed position of the capillary a light beam encounters the particle and the fluorescence signal as well as the scattered light (sideward and forward) is detected (left part). An emerging approach is the recording of a specific signal profile (right part) which leads to a more detailed characterization and even visualization of each particle. (B) The final results of FC measurements are dot plots considering multiple detected parameters, e.g., fluorescence, forward scattering or sideward scattering. (C) Exemplary, the BD FACS Calibur as a flow cytometer enabling particle detection and characterization.