Multi-parameter, computer controlled operation of a FACS II cell sorter

Area of Science:

• Cell biology
• Biotechnology
• Instrumentation engineering

Background:

• The Fluorescence-Activated Cell Sorting (FACS) II cell sorter is a critical tool in biological research.
• Limitations in the original FACS II's analog signal processing and pulse height analysis (PHA) hindered optimal performance and versatility.
• The need for improved precision and flexibility in cell sorting applications was apparent.

Purpose of the Study:

• To enhance the operational ease and versatility of the FACS II cell sorter.
• To replace the original pulse height analyzer (PHA) with a more advanced computer-based system.
• To improve the purity and efficiency of sorted cell fractions.

Main Methods:

• The original analog pulse height analyzer (PHA) and associated circuitry were replaced with a computer-based dual parameter PHA and a single channel analyzer (SCA).
• An ND620 LSI-11 based PHA was integrated for generating sorting decisions.
• Interfacing electronics were redesigned using an interchangeable circuit board to manage signal processing.

Main Results:

• The upgraded system demonstrated improved ease of operation and increased versatility.
• Sorting windows could be defined with greater flexibility across single or dual parameter histograms.
• The single channel analyzer (SCA) improved sorted fraction purity by triggering an abort circuit during the PHA's dead time.

Conclusions:

• The computer-based PHA and SCA upgrade significantly enhances FACS II cell sorter capabilities.
• The implemented principles are applicable to improving other cell sorting instruments.
• This advancement offers greater precision and flexibility in cell sorting for various research applications.