There was once a time when Flourescence Activated Cell Sorting (FACS) was quite an ordeal. Around 1972, Geoff was working at University College, London. David Capellaro arrived from Palo Alto. He brought with him the Becton Dickinson prototype of the FACS machine – FACS1. Geoff worked for three years with David to put FACS1 to good use to describe the common ALL antigen (cALL, CD10). 

FACS1 occupied an entire room. The laser was large, and required a huge supply of water for cooling. The laser was tuned with reference to displays on two square wave oscilloscopes. The percentage of positive cells was recorded by moving cursors on the display and reading off numbers. A record of the fluorescent profile was taken by sliding a camera in place and taking a Polaroid photograph. The nozzle blocked endlessly, and removal and a sharp tap soon resolved. From those early days, here are the fluorescence profiles (Polaroid photograph) for three specific anti-cALL (CD10) sera against acute lymphoblastic leukaemia cells.
The University of Wroclaw has an outreach programme for students at secondary schools. Ewa Marcinkowska gave up her Saturday to teach students how to analyse the nature of cells by FACS. And, as all our Fellows know, FACS is now very much a routine matter

fluorescence profiles