Performance Assessment of a Liquid Handling Robot

Conclusion

 

In order to determine the liquid volume transferred by the liquid handling robot, the Gravimetric Method, Single-Dye Fluorescence-Based Method and Dual-Dye Absorbance-Based Method have been developed and implemented. Based on the results obtained from the Gravimetric Method, the liquid handling robot has been calibrated for the critical volumes ranged from 5 μL to 20 μL. Two sets of acceptability criteria have been set for performance qualification: for volume > 10 μL, inacc < ±10% and CV < 10%; for volume ≤ 10 μL, inacc < ±20% and CV < 10%. The post-calibration performance of the robot has been qualified to be accurate and precise in most circumstances by meeting the acceptability criteria.

 

The Gravimetric Method benefits from its simplicity and it has been shown to be suitable for individual channel assessment. By comparing the photometric results with the gravimetric results, the applicability and validity of the photometric methods have been demonstrated. For the multichannel systems, the Single-Dye Fluorescence-Based Method can cover the volume larger than 50 μL, whereas the Dual-Dye Absorbance-Based Method has been proved to measure volume liquid as low as 5 μL. On the basis of these robust methods, a standardized operating protocol has been proposed for liquid transfer quality control. This protocol is applicable to the performance assessment for other liquid handling robots.

 

Finally, after performance assessment and calibration, the optimized robot delivers liquid as requested, which is critical for assay interpretation in life science research. The liquid transfer processes are repeatable such that the consistency in downstream results is assured. High quality in liquid handling also minimizes the economic loss in high-throughput screening operations. When it comes to high accuracy in low nanolitre liquid dispensing, acoustic droplet ejection shows a comprising potential in the future laboratory automation field.