Webcam-based flow cytometer using wide-field imaging for low cell number detection at high throughput.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Cell Biology

Background:

• Traditional flow cytometry faces limitations in detecting low cell numbers and requires expensive equipment.
• Current methods struggle with high throughput and sensitivity for rare cell analysis.

Purpose of the Study:

• To develop and validate a novel, low-cost flow cytometer utilizing a webcam for enhanced sensitivity and throughput.
• To assess the device's capability for detecting rare cells in large volumes, applicable to clinical diagnostics.

Main Methods:

• Integration of a high-speed webcam, a 450 nm laser module, and a 2D flow cell for area-excitation and rapid cell interrogation.
• Utilized a 2D flow cell to overcome hydrodynamic focusing limitations, enabling lower cell velocities and full webcam frame rate imaging.
• Tested sensitivity and throughput using fluorescently tagged polystyrene beads and THP-1 human monocytes in buffer and blood.

Main Results:

• The webcam-based flow cytometer detected fluorescent cells at concentrations as low as 1 cell/mL at 500 μL/min flow rates.
• Detection effectiveness ranged from 59% at 1 cell/mL to 84% at 100 cells/mL compared to microscopy.
• Demonstrated successful detection in blood samples with high accuracy and narrow confidence intervals.

Conclusions:

• The developed low-cost flow cytometer offers high sensitivity and throughput, overcoming limitations of conventional systems.
• The device is suitable for rare cell detection, including circulating tumor cells, and has potential for point-of-care applications.
• Its simplicity and low cost make it ideal for resource-poor settings and global health initiatives.