A novel device for buffy coat collection
BioTechniques. 2025;77(5-6):223-230. DOI 10.1080/07366205.2025.2534299.
How to cite
AMA
Hardy KC, Arrigo L, Campbell J, Fiedler J, Fiedler P. A novel device for buffy coat collection. BioTechniques. 2025;77(5-6):223-230. doi:10.1080/07366205.2025.2534299APA
Hardy, K. C., Arrigo, L., Campbell, J., Fiedler, J., & Fiedler, P. (2025). A novel device for buffy coat collection. BioTechniques, 77(5-6), 223-230. https://doi.org/10.1080/07366205.2025.2534299BibTeX
@article{hardy2025novel,
title = {A novel device for buffy coat collection},
author = {Hardy, K. C. and Arrigo, L. and Campbell, J. and Fiedler, J. and Fiedler, P.},
journal = {BioTechniques},
volume = {77},
number = {5-6},
pages = {223--230},
year = {2025},
doi = {10.1080/07366205.2025.2534299}
}The buffy coat is the paper-thin white layer between plasma and red cells in centrifuged blood, and it holds the rare circulating tumor cells that liquid biopsy depends on. Pulling it off the tube cleanly is the hard part: simple pipetting and density-gradient methods lose cells or drag red cells along, while the instrument-based alternatives are costly.
The authors built a low-cost, 3D-printed device with eight radial channels that gently aspirates the buffy coat using a standard pipette controller. Spiking myeloma cells into blood to model CTCs, they recovered 89% to 98% of the tumor cells across a range of concentrations, then identified real CTCs in blood from multiple myeloma and MGUS patients, enumerated on an automated CyteFinder scanner.
Key findings
- The 3D-printed device recovered spiked tumor cells at high efficiency across the tested range. Myeloma cells spiked into blood as model CTCs were recovered at 89% at the lowest concentration (12 cells/mL) and up to 98% at 300 cells/mL, with recovered cells counted on the automated CyteFinder system.
- The CyteFinder scanner identified circulating tumor cells in blood from multiple myeloma and MGUS patients. From the device-collected buffy coat, an average of 342 CTCs per mL was found in a newly diagnosed, untreated myeloma patient versus 25 CTCs per mL in an MGUS patient, each confirmed by a DAPI-positive, CD138/CD56/BCMA-positive, CD8-negative signature.
- The device recovered more of the buffy coat than a standard transfer pipette. Across 10 patient samples it yielded 1.8-fold higher white blood cell concentrations (an 82% increase), a difference that reached statistical significance (Wilcoxon signed-rank, p = 0.01086).
CyteFinder in the methods
“The identification of CTCs isolated from MM and MGUS patients using our 3D printed device was simplified and automated by using the Cytefinder™ scanner and a software algorithm to identify cells expressing a combination of fluorescent surface markers. A CTC cell was confirmed as having a nucleus (DAPI), positive CD138, CD56 and BCMA staining with negative CD8 fluorescence.”
— Hardy et al., BioTechniques (2025), Results, “Visualization of CTCs from clinical samples obtained with novel device”
Why it matters for CyteFinder users
If you are weighing CyteFinder for rare-cell work, look at the role it played here. The device the authors built solves the front end, pulling a clean buffy coat off the tube, but a buffy coat is only useful if you can then find the handful of tumor cells hiding among millions of leukocytes. That is the step the CyteFinder scanner carried: its automated cell-finding software scanned each slide and flagged the cells whose fluorescence matched the target signature, first for the spiked myeloma cells used to measure recovery, then for real circulating tumor cells in blood from multiple myeloma and MGUS patients. Two things matter for your own workflow. Because the readout is imaging-based rather than flow-based, you can localize, phenotype, and count CTCs directly on the slide even when they sit below the threshold where flow cytometry loses them. And because the scan runs automatically against a defined marker combination, the enumeration stays consistent from sample to sample rather than resting on a single operator's eye, which is what let the authors report clean per-patient CTC counts across two disease states.
