Flow Cytometry Protocols

METHODS IN MOLECULAR BIOLOGY TM TM Volume 263 Flow Cytometry Protocols SECOND EDITION Edited by Teresa S. Hawley Robert G. Hawley 1 Flow Cytometry An Introduction Alice L. Givan Summary A flow cytometer is an instrument that illuminates cells (or other particles) as they flow individually in front of a light source and then detects and correlates the signals from those cells that result from the illumination. In this chapter, each of the aspects of that definition will be described: the characteristics of cells suitable for flow cytometry, methods to illuminate cells, the use of fluidics to guide the cells individually past the illuminating beam, the types of signals emitted by the cells and the detection of those signals, the conversion of light signals to digital data, and the use of computers to correlate and analyze the data after they are stored in a data file. The final section of the chapter will discuss the use of a flow cytometer to sort cells. This chapter can be read as a brief, self-contained survey. It can also be read as a gateway with signposts into the field. Other chapters in this book will provide more details, more references, and even some controversy about specific topics. Key Words Flow cytometry, fluidics, fluorescence, laser. 1. Introduction An introductory chapter on flow cytometry must first confront the difficulty of defining a flow cytometer. The instrument described by Andrew Moldavan in 1934 (1) is generally acknowledged to be an early prototype. Although it may never hav