Flow cytometer electronics

Flow cytometers, like all things electronic, have under-gone rapid evolution since the introduction of the first commercial instruments 30 years ago. Cytometers then had so little automation and sophistication that the operator had to be expert in many different scientific disciplines to be able to coax any data at all out of the instrument. But trends in electronic components toward higher speed, smaller size, and lower power consumption have allowed the instruments to become faster, more sensitive, and actually quasi-intelligent. Automation of complex processes that once required considerable operator expertise, such as running a high-speed sort or correctly compensating a multicolor experiment, has expanded the number of flow cytometry applications and the number of flow cytometry users; there is no reason to expect that trend to stop. This review discusses the electronic components of a current "generic" flow cytometer from a functional point of view with the hope that a better understanding of what is going on "inside the box" will lead to a better understanding of how operator-selectable instrument settings can influence the quality of the data produced. (C) 2004 Wiley-Liss, Inc.