Certain substances can stain the LightGuide flow cell cartridges causing a loss in transmission and consequently a loss in performance. The LightGuide flow cells can be restored via an advanced cleaning procedure. This cleaning procedure is described in the LightGuide supplement (V6708). A further measure for cleaning your flow cell is the application of special cleaning concentrate for cuvettes, (e.g. Hellmanex III from Hellma Analytics). In this case, the manufacturers' instructions should be followed.