Biomedical Engineering Reference
In-Depth Information
INTRODUCTION TO FLOW
CYTOMETRY
E
LIZABETH
R
AVECHE
,F
ATIMA
A
BBASI
,Y
AO
Y
UAN
,E
RICA
S
ALERNO
,
S
IDDHA
K
ASAR
,
AND
G
ERALD
E. M
ARTI
1.1
INTRODUCTION
This chapter presents, in basic terms, the concepts and principles of flow cytometry.
Numerous topics and articles describing flow cytometers and their use in a clinical and
biomedical research setting have been published [1-7]. In this chapter, flow
cytometers will be discussed from their infancy arriving at the current instrumentation
that allows for detection of numerous features of individual cells or particles,
including determination of size and granularity, surface marker expression, DNA
content, intracellular protein expression, and function. The key to flow cytometers is
that the analysis is done on cells in suspension [8-10]. The analysis of individual cells
(or particles) rather than the whole population allows for detection of multiple
properties measured on the same cell. The detection is rapid (as fast as the cell in
the fluid sheath passes through the laser beam). In addition to analysis of individual
cells, some types of flow cytometers can physically sort cells based on signals
associated with the parameters being detected. The term fluorescence-activated cell
sorter or FACS has been adopted to refer to this type of analysis [11]. Flow cytometry
is a very useful tool for both clinical diagnosis and scientific research. The history of
flow cytometers has been the subject of numerous reviews [12-20]. The first flow
cytometers were introduced in the mid-1970s and first used for DNA analysis and
leukemia immunophenotyping [7, 21-25]. A further impetus to bring flow cytometers
to the forefront of clinical labs came in the early 1980s with the discovery that
individuals infected with the HIV virus developed AIDS, which could be monitored
