Red Blood Cell (RBC) related illnesses and abnormalities are prevalent in our world, however appropriate access to diagnostic care is limited due to financial constraints and accessibility of technology. This study introduces a novel cell tracking velocimetry (CTV) system that precisely quantifies individual RBC properties, including magnetic susceptibility, volume, and density. The system consists of a microfluidic chamber positioned within an assembly of permanent neodymium magnets generating a controlled magnetic energy field gradient of 191.82 TA/mm² [1,2]. A portable microscope camera records cell trajectories at 60 frames per second, with subsequent analysis performed using ImageJ's FIJI plug-in TrackMate. The primary purpose of this study is to establish magnetic susceptibility metrics through velocity and trajectories measurements for blood cells and determine hemoglobin and iron content in individual cells from its measured magnetic properties in healthy, aging and disease conditions. The system was initially validated using polystyrene beads of known properties before being applied to characterize dysfunctional (sickle) RBCs as well as RBCs stored in additive solution-3 (AS-3) over an extended period of time. Calibration with healthy, fresh RBCs established baseline measurements, confirming the system's ability to simultaneously detect subtle variations in morphology, volume, and hemoglobin content in individual cells. The CTV technology provides a rapid (< 30 minutes per sample), label-free, and non-invasive method for analyzing RBC properties, with significant implications for blood banking and transfusion medicine as well as for the diagnosis of hematology conditions [3].
[1] Gómez-Pastora, J.; Kim, J.; Weigand, M.; Palmer, A.F.; Yazer, M.; Desai, P.C.; Zborowski, M.; Chalmers, J.J. Potential of Cell Tracking Velocimetry as an Economical and Portable Hematology Analyzer. Scientific Reports 12 (2022) 1-12.
[2] Kim, J.; Gómez-Pastora, J.; Weigand, M.; Gilbert, C.; Walters, N.A.; Reátegui, E.; Palmer, A.F.; Yazer, M.; Zborowski, M.; Chalmers, J.J. Quantification of the mean and distribution of hemoglobin content in normal human blood using cell tracking velocimetry. Analytical Chemistry 92 (2020) 1956-1962.
[3] Weigand, M.R.H.; Gómez-Pastora, J.; Kim, J.; Kurek, M.T.; Hickey, R.J.; Irwin, D.C.; Buehler, P.W.; Zborowski, M.; Palmer, A.F.; Chalmers, J.J. Magnetophoretic and spectral characterization of oxyhemoglobin and deoxyhemoglobin: Chemical versus enzymatic processes. PLoS ONE 16 (2021) e0257061.
