Bio-Rad Bio-Plex Pro™ Magnetic Cell Signaling Assays - Manual (Page 4)

Principle
Technology
The Bio-Plex
® suspension array system is built upon the three core
elements of xMAP technology:
n
Fluorescently dyed microspheres (also called beads), each with a distinct
color code or spectral address to permit discrimination of individual tests
within a multiplex suspension. This allows simultaneous detection of up to
500 different types of molecules in a single well of the 96-well microplate
on the Bio-Plex
® 3D system, up to 100 different types of molecules on the
Bio-Plex ® 200 system, and up to 50 different types of molecules on the
Bio-Plex ® MAGPIX ™ system
n
A dedicated plate reader. The Bio-Plex 200 and Bio-Plex 3D systems are
flow cytometry–based instruments with two lasers and associated optics
to measure the different molecules bound to the surface of the beads. In
the Bio-Plex MAGPIX system, the entire sample load volume is injected into
a chamber where the beads are imaged using LED and CCD technology
n
A high-speed digital signal processor that efficiently manages the
fluorescence data
Assay Format
Bio-Plex Pro
™ assays are essentially immunoassays formatted on
magnetic beads. The assay principle is similar to that of a sandwich
ELISA (Figure 1). Capture antibodies directed against the desired
biomarker are covalently coupled to the beads. Coupled beads react
with the sample containing the biomarker of interest. After a series of
washes to remove unbound protein, a biotinylated detection antibody
is added to create a sandwich complex. The final detection complex is
formed with the addition of streptavidin-phycoerythrin (SA-PE) conjugate,
which serves as a fluorescent indicator or reporter.
2