Performance Assessment of a Liquid Handling Robot
Volume Determination of Dispensed Microlitre Droplets
DISCUSSION
Agreement among the Observed Facts
This work was aimed to characterize the liquid delivery performance of the Multichannel Pod and the Span-8 Pod. For this purpose, the Gravimetric, photometric methods were implemented to verify the amount of volume transfer. In this chapter, the conformity among results obtained via different approaches will be discussed to verify the validity of these approaches.
Note that because of the drifts in the equipment, it may be statistically impossible to obtain an exactly same result within relatively limited replicates of measurements.
Error Sources Analysis
The volume verification of liquid handling robot requires not only a high degree of accuracy, but also a good knowledge of the sources of error that can obscure the performance of the liquid handling robot. Unless these variables are tightly controlled, it is difficult to distinguish the measured volume bias are accounted for outside of accuracy limits or caused by the systematic errors in the volume verification procedures.
Strengths and Limitations of the Three Methods
Each method has its own strengths and limitation. The analysis of their strengths and limiatations allows us to select the proper method for a particular circumstance. After that, a standardized performance assessment protocol can be proposed.
Further Investigation of Liquid Handling in Low Nanolitres
The development of robotic systems has brought volume in biological assays from millilitre to microlitre scale. However, further reduction to nanolitre or picolitre scale is more challenging, because the currently available systems, which are mostly based on contact dispensing technology, would damage the living cells and fragile macromolecules by physical contact (Ellson et al., 2003). Therefore, for lower volume dispensing, a gentle and accurate liquid transfer technique is of increasing interest.
