Rmax: A systematic approach to evaluate instrument sort performance using center stream catch.

Area of Science:

• Cellular Biology
• Biotechnology
• Analytical Chemistry

Background:

• Sorting performance is crucial for cell-based research and diagnostics.
• Traditional metrics like Purity, Yield, and Recovery have limitations, particularly Yield and Recovery, due to measurement complexities.
• Purity alone is insufficient for comprehensive performance evaluation, necessitating accurate Yield and Recovery metrics.

Purpose of the Study:

• To introduce a novel, simplified metric (Rmax) for evaluating instrument sort Recovery.
• To overcome the challenges associated with traditional Yield and Recovery measurements, such as re-sampling and absolute counting.
• To provide a practical tool for daily quality control and performance assessment of cell sorters.

Main Methods:

• Developed a new metric, Rmax, defined as the ratio of sorted particles to original particles.
• Rmax calculation relies on measuring population ratios in pre-sort samples and waste/center streams.
• This method avoids re-sampling the sorted fraction and absolute particle counting.

Main Results:

• Rmax offers a feasible way to measure instrument sort Recovery without perturbing the sorted fraction.
• The metric successfully bypasses the need for absolute counting, which is often error-prone and impractical for rare or precious samples.
• Rmax can be calculated during the sorting process, enabling real-time performance monitoring.

Conclusions:

• Rmax provides a robust and accessible method for assessing cell sorter performance, particularly Recovery.
• This metric is valuable for troubleshooting instrument parameters like drop-charge delay and identifying failures.
• Rmax is especially beneficial for experiments involving rare cell populations and for routine quality control.