A method and apparatus for an automated biological reaction system is provided. In the processing of a biological reaction system, there is a need for consistently placing an amount of liquid on a slide. In order to accomplish this, several methods are used including a consistency pulse and a volume adjust means. Moreover, in order to reliably operate an automated biological reaction system, the dispenser must be reliable, easy to assemble and accurate. Among other things, in order to accomplish this, the dispense chamber is substantially in line with the reservoir chamber, the reservoir chamber piston is removed, and the flow of liquid through the dispenser is simplified. Further, in order to operate the automated biological reaction system more reliably, the system is designed in modular pieces with higher functions performed by a host device and the execution of the staining operations performed by remote devices. Also, to reliably catalog data which is used by the automated biological reaction system, data is loaded to a memory device, which in turn is used by the operator to update the operator's databases. The generation of the sequence of steps for the automated biological reaction device based on data loaded by the operator, including checks to determine the ability to complete the run, is provided.