Modular monitor and control system for cell sorter stream

A modular monitor and control system configured to monitor the fluid jet and droplet formation region in a stream-in-air particle sorter and control flows of sheath fluid and particle suspension sample via first and second valves, the system comprising:

• a processor configured to:
• receive digital video image signals of the fluid jet and droplet formation region in the sorter;
• continuously analyze the digital video image signals to determine a significant change in the digital image signal;
• and trigger an alert signal in response to a determined significant change, the alert signal including at least a relay switch activation signal;
• and
• at least one relay switch separate from the particle sorter and in communication with the processor, the at least one relay switch connected with the first and second valves and configured to close the first and/or second valve upon activation of the at least one relay switch via the relay switch activation signal.