Random Error

The causes of increased random error are generally more difficult to determine because of their random nature. Random errors are more likely due to bubbles in the reagent, reagent lines, sampling or reagent syringes, an improperly mixed or dissolved reagent, pipette tips not fitting properly, a clog in the pipettor, imprecise pipettor, the power supply, and even power fluctuations.

Many of these problems can be detected by inspecting the machine during operation. If a careful inspection provides no clues, consult the manufacturer's troubleshooting guides and recommendations.

If a run is repeated and the controls are acceptable but concern remains that a problem still exists, perform a precision run using ten back-to-back determinations on the same patient sample. This precision run may help identify further imprecision problems. Duplicate analysis of patient specimens is also recommended when monitoring random error problems.