ObservationPossible causesRecommended solutions Excessive amount of debris in displayThreshold level is too lowIncrease the threshold level Sheath filter is dirtyReplace the filter. Contact FMCF staff Flow cell is dirtyPrime the instrument several times. Contact FMCF staff Dead cells or debris in sampleExamine the sample under a microscope Sample is contaminatedRe-stain the sample, ensure tube is clean Stock sheath fluid is contaminatedContact FMCF staff