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.
By Huijin Dong, Zheng Ouyang, Jane Liu, and Mohammed Jemal
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.
By Keith J. Albert, John Thomas Bradshaw, Tanya R. Knaide, and Alexis L. Rogers
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.
Nearly all assays performed within a microtiter plate are volume dependent. In turn, all concentrations of biological and chemical components in these assays, as well as the associated dilution protocols, are volume dependent. Therefore, it is imperative to quantify the volumes transferred to and from an assay. A volume verification method, which can be used […]
By John Thomas Bradshaw, Richard H. Curtis, Tanya R. Knaide, and Benjamin W. Spaulding
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.
Equipment calibration is a necessary and common fact of life in regulated laboratories, and the decision on how to calibrate often begins with a simple choice of whether to contract an outside service, or to keep it “in-house” and do it yourself. Laboratories have a variety of reasons for choosing in-house calibrations. Whether to enhance […]
The answers to these FAQ’s were developed in consultation with Dr. Burkhard Winter of the German Standards Institute DIN, and are based on definitions given in International Standards. Dr. Winter is Secretary of ISO Technical Committee 48, which has jurisdiction over the ISO 8655 series of standards and was responsible for editing the 8655 series […]