1) Error in assay preparation, samples/well do not contain enough beads

2) Incorrect target values used in calibration. Check that target values in calibration dialog box match the values on CAL1 and CAL2 bottles.

3) Sheath reservoir low or empty. Refill sheath reservoir. Check that the bottle (or SD) is tightly connected to the instrument.

4) Waste line/bottle not connected properly. Make sure that it clicks into place.

5) Check for leaks from the sample probe, if there is leaking this suggests a clog in the fluidic line from the cuvette to the sample probe. Follow the unclog routine.

6) Waste bottle is overfilled, make sure the waste bottle cap is vented and that there is no pressure inside the waste bottle.

7) Incorrect regions were selected when preparing the assay. Verify regions chosen during assay preparation.

8) It is important that the beads be vortexed for 30 seconds and then sonicated for at least 30 seconds prior to beginning the assay to break up the aggregates.

9) Beads will be lost if the contents of the plate are emptied from the top, rather than from the bottom of the filter plate.
Make sure to keep the plate in the upright position at all times.

10) Prevent the filter plate membrane from tearing, place pipette tips on the side of the well, rather than straight down onto the membrane when dispensing liquid into the wells.

11) Air enters the tubing and lines of the system.Air can enter the lines when the volume of the bead suspension is insufficient for the height of the probe of the instrument. See Technote #13