In light of the multitude of error sources, it is easy to overlook the environmental conditions in the laboratory, and the effects they can exert on the quantitative dispensing of liquid with handheld pipettes.
Regulations are not keeping pace with new technology, leading to a lack of relevant calibration standards or guidelines. Laboratories need to update their calibration procedures to measure and document microliter/nanoliter volumes quickly and accurately.
A series of experiments, using the default pipetting parameters, was performed which demonstrated that the difference in the reported volume was due to a dilution effect by the system liquid of the liquid handler and did not indicate an error in the delivered volumes.
Accurate and reliable adjustment of liquid handler protocols for varied reagent types could have far reaching adoption in all scientific communities. Using this methodology, target aliquots of multiple solutions were dispensed with a calibrated syringe and subsequently validated via dual-dye ratiometric photometry.
This paper describes a new approach, which is based on dual dye, dual-wavelength photometry, for accurately measuring each dilution step in a multistep dilution protocol. The theory behind this method is described, as well as an experimental demonstration of the prescribed approach.