The calibration of flow cytometers in the clinical laboratory is
of primordial importance for the interlaboratory comparison of
quantitative and classification results.
Brightly fluorescent alignment beads are used to control
the overall optical and electronic performance of a flow cytometer.
The measurement of a mixture of typically four fluorescent beads
with known amounts of antibody binding sites or bound antibodies permits
the calibration of the fluorescence scale of a flow cytometer
in "bound fluorescent antibody molecules". A non fluorescent
bead characterizes the assay noise level of the flow cytometer.
Besides the determination of the number of cell bound antibody molecules,
the "sample window" of flow cytometers can be determined in absolute
i.e. instrument independent terms (e.g the lower and upper threshold
of displayed fluorescences may range from 200 to 2.000.000 molecules in a
four logarithmic decade instrument).
Suitable calibration beads are available from different commercial
sources. The characteristics and performance of various beads are displayed
in the following chapters:
Becton Dickinson
USA:
Germany:
Flow Cytometry Standards Corporation (FCSC)
USA:
P.O.Box 194344
San Juan, PR 00919-4344
USA
Tel: +1/787/2741245
Fax: +1/787/7583267
E-mail: 73437.2722@compuserve.com
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