Importance of Integrating a Volume Verification Method for Liquid Handlers: Applications in Learning Performance Behavior

Abstract

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 to quantify the amount of transferred volume, is an essential component that enables proper interpretation of experimental results. A volume verification method can be used to help an operator optimize volume transfers as well as troubleshoot automated methods. Moreover, these methods can be used to compare performance between liquid handlers, show dispense drift over time, compare channel-to-channel (tip-to-tip) reproducibility, or statistically compare individual dispenses from a multisequential dispense. The focus of this paper, in part, is to discuss some of the many situations where a volume verification method should be implemented. This paper addresses important factors and their associated applications in understanding liquid handler behavior and is not meant to be specific to the volume verification process or the specific liquid handlers used. A robust and reliable volume verification method allows for measurement of transferred volumes at all levels in assay development, from a pure research level to a highly regulated laboratory environment. The goal is to achieve liquid delivery quality assurance through accurate and precise measurement of critical volume transfers. (JALA 2007;12:172–80)