Bio-Rad Bio-Plex® Precision Pro™ Human Cytokine Assays - Manual (Page 13)

11
Prepare Coupled Magnetic Beads
Protect the beads from light by covering the tubes with aluminum foil.
Keep all tubes on ice until ready to use.
1. Vortex the coupled beads (25x) at medium speed for 15–20 sec.
2. Prepare a sufficient volume of coupled beads (1x) using assay
buffer. Each well requires 2 µl of coupled beads (25x) adjusted to a
final volume of 50 µl with assay buffer (refer to the example below).
Calibrate Vacuum Apparatus
The vacuum apparatus must be calibrated at the beginning of the assay
to ensure an optimal bead yield. For more detailed instructions, refer to
the Bio-Plex suspension array system hardware instruction manual.
1. Prewet all the wells of a 96-well filter plate with 100 µl of assay buffer.
2. Place the filter plate on the vacuum apparatus and turn on the
vacuum to the maximum level.
3. Press on the filter plate and note the time required to remove the
buffer from the wells by vacuum filtration. The evacuation time
should be 2–5 sec.
If the evacuation time is <2 sec, the pressure is too high. Open the
vacuum control valve slightly and repeat steps 1–3.
If the evacuation time is >5 sec, the pressure is too low. Close the
vacuum control valve slightly and repeat steps 1–3.
# of Wells 25x Beads (µl) Assay Buffer (µl) Total Volume (µl)
96
48
32
24
240
120
80
60
5,760
2,880
1,920
1,440
6,000
3,000
2,000
1,500
Example Bead Calculations