2.3.3.2. Microplate reader

The uniformity absorbance reading of the microplate reader maintenance checking is done by pipetting 200 μl of 1:1500 green food coloring in water in the first row (Row A) of a 96-well microtiter plate. Mean, SD, 1.5SD and CV of the readings are then determined. A scatter plot should be graphed for the individual readings with horizontal lines for mean and mean � 1.5SD. The number of readings outside mean � 1.5SD is determined and its percentage is calculated. Percentage error should be ≤20%. If it is not achieved, the maintenance check should be repeated and a request for calibration or repair should be lodged if problem persists. Maintenance check up every three-monthly has to be performed.
