Development and Characterization of a Mass Cytometer for Single-Cell Analysis

Flow cytometry is widely used for single-cell analysis but is constrained by a limited number of detection channels (typically<12) and by spectral overlap between fluorophores. Mass cytometry, based on mass spectrometric detection principles, addresses these limitations by employing metal isotope labeling, enabling a substantial expansion of detection channels (>40) and effectively reducing inter-channel signal interference. Nevertheless, the high cost of imported mass cytometers has significantly hindered their widespread adoption in both scientific research and clinical diagnostics. In this study, the development of a domestically manufactured mass cytometer was reported, representing a significant advancement in high-end analytical instrumentation. The system integrated a pneumatic sample introduction module, an inductively coupled plasma (ICP) ion source, a quadrupole ion transmission system, a time-of-flight mass spectrometer (TOF MS), and a high-frequency data acquisition module. Performance evaluation was conducted using multi-element metal standard solutions. The instrument achieved a full mass range resolution exceeding 550 (full width at half maximum, FWHM). At a sample flow rate of 30 μL/min, the sensitivity for ¹⁵⁹Tb⁺ reaches 9×10⁵ cps/pg. Limits of detection are determined to be 0.4 ng/L for Cs, 0.2 ng/L for Tb, and 0.04 ng/L for Ir. An 8 h mass stability test demonstrates a mass drift of less than 0.1 u. Furthermore, the detection of cell surface protein expression using the developed instrument shows high concordance with results obtained from a leading commercial system (Helios). The successful construction and validation of this instrument fill a critical technological gap in the domestic market for high-performance mass cytometry. Its demonstrated resolution, sensitivity, stability, and analytical accuracy establish a robust platform for high-dimensional single-cell analysis. This achievement not only supports the expansion of multi-parameter cellular studies in basic research, but also holds substantial potential for translational applications in clinical diagnostics and precision medicine.