𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Further developments of a microscope-based flow cytometer: Light scatter detection and excitation intensity compensation

✍ Scribed by Harald B. Steen


Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
517 KB
Volume
1
Category
Article
ISSN
0196-4763

No coin nor oath required. For personal study only.

✦ Synopsis


Abstract

A microscope‐based flow cytometer, which is based on a new flow system, has been extended to include light scatter detection, dual parameter fluorescence analysis, and a device which compensates for variations in excitation light intensity. A dichroic mirror splits the fluorescence into two spectral components that are further purified by additional filters situated in front of the photomultiplier tube detectors (PMT). Light scatter detection is obtained by a dark field configuration. An objective focuses the scattered light emitted within the dark field onto an adjustable slit in front of a PMT. Resolution of light scatter histograms of 1.5‐m̈m latex spheres is about CV = 2.5%. Dual parameter analysis revealed a linear correlation between the light scatter signal and fluorescence of cells stained with fluorescein isothiocyanate, indicating that the light scatter signal is closely proportional to cell dry mass. The instrumental light scatter, which is proportional to the excitation light intensity, gives rise to a DC signal. This signal regulates the fluorescence signal amplifiers so that these signals are compensated for fluctuations in the excitation light intensity.