How to test volume accuracy

Answer

1. Dye some water or your reagent with a colour using food dye or some scientific grade dye & be sure to incorporate it thoroughly. 

2. Measure the weight of the Multi Well Plate (MWP) before any liquid is added

3. Use SQWERTY to transfer or Multi-dispense dyed reagent into the MWP. Do this for at least 24 targets. 

4. Measure the weight of the MWP after the liquid has been added & calculate the change.

5. Divide the mass change by the density of the reagent to calculate the total volume of liquid in the MWP (ml).

6. Use a spectrometer to measure the absorbance at the wave length for your colour. Ideally the results should be between 0.3 and 1.8 for the spectrometer results to be the most accurate.

7. Repeat the above with your preferred manual pipette

The absorbance results can't tell you the exact volume but the standard deviation will advise you of the inter-well consistency and highlight anomalous wells. The weight change will be accurate of the total volume of liquid transferred across the entire workflow. The data isn't always accurate for inspection of individual wells and will be greatly influenced by anomalous data. 

Every change to the liquid parameters, the volumes, the pipette module, the labware etc. has the potential to change the results of this experiment.

The MWP and pipette tips should be in good shape with no damage. The reader needs to have been calibrated. The solutions need to be well mixed and have no bubbles. Do Not touch the bottom of the MWP (or at least the wells that contain the solution).

If you find the accuracy results are not up to standard, adjust the workflow to optimise the transfers.

If you require more information please contact [e-mail] for assistance.