In Flow Cytometry, What Is; A Parameter; A Histogram Channel; The Count In A Histogram - SYSMEX CyFlow Ploidy Analyser Instrument Operating Manual

Instrument Operating Manual
fluorescence. In the CyFlow
are collected in the DNA-DAPI channel and the DNA-PI channel, respectively.
Next to the fluorescence scattered light is detected in the SSC channel only of
®
CyFlow Ploidy Analysers equipped with a Nd-YAG solid state laser.
A list of dedicated Sysmex Partec reagent kits is contained in the Technical
Specification section of the Appendix of this manual.
2.5

In Flow Cytometry, what is...

... a parameter?

In flow cytometry, parameter denotes a measured property of the particles. Frequently, a
parameter is synonymous to an optical channel. E.g. an instrument with 2 parameters is
equipped with 2 optical detectors.

... a histogram channel?

The measured signal intensity is assigned to one of 65536 quantity classes or channels.
In a one-parameter histogram the channels are represented on the x-axis.

... the count in a histogram?

The number of cells being assigned to a given channel is referred to as channel content
or simply count. In a one-parameter histogram, the count is shown on the y-axis.

... a peak?

All cells having about equal characteristics among the analysed cell property (e.g. content
of a specific constituent like DNA), form a peak. In the case a of typical DNA histogram
one peak represents the G1 and another peak (with twice the channel value) represents
the G2/M phase of the cell cycle.

... background in a histogram?

Histograms sometimes show undesired signals in the lower channels, frequently called
´noise´ or ´background´. These signals may originate from cell or nuclei fragments or
other particles resulting from sample preparation. In case of high signal amplification,
background can also be caused by particle contaminated sheath fluid.
...the lower level (L-L) or threshold?
The lower level (L-L) threshold is a mean to suppress background signals. Signals below
the lower level are rejected from the signal acquisition. To exclude noise from a histogram
already acquired, a region-gate can be used.
Sysmex Partec GmbH
Am Flugplatz 13, 02828 Görlitz, Germany · Phone +49 3581 8746-0 · Fax +49 3581 8746-70 · info@sysmex-partec.com ·
®
Ploidy Analyser the relevant fluorescence signals
CyFlow® Ploidy Analyser Rev-03_2104-10-22
www.sysmex-partec.com
10 / 47