Agilent Technologies NovoCyte Quanteon, Руководство оператора, Страница: 41 / 148

Introduction
NovoCyte Quanteon Flow Cytometer Operator's Guide 41
NOTE
To set the flow rate, please refer to Set Sample Acquisition Conditions in this guide
and relevant sections in NovoExpress Software Guide .
Electronics System
Pulse Generations
As cells or other particles pass through a focused laser beam, they scatter the
laser light and can emit fluorescence. Because the laser beam is focused on a
small spot and particles move rapidly through the flow cell, the scatter or
fluorescence emission has a very brief duration, usually only a few microseconds.
This brief emission of light is converted into an electrical signal (a pulse shown in
Figure 14) by the photodetectors.
1 A pulse begins when a particle enters the laser beam. At this point, both the
beam intensity and signal intensity are low.
2 The pulse reaches a maximum intensity or height when the particle reaches
the middle of the beam, where the beam and signal intensity are the brightest.
The peak intensity, or height of the pulse, is measured at this point.
3 As the particle leaves the beam, the pulse trails off below the threshold.
Figure 14. Illustration of Pulse Generation