The embodiments disclosed relate to determination of an item of interest in a sample. In one method, a process path comprising a process lane including a process step performance lane where a process step is performed, and a process step avoidance lane where the process step is avoided is provided. A container holding the sample is moved along the process path. The sample is introduced to the container. A reagent is introduced to the container. The sample and the reagent are mixed in the container. The container is selectively positioned in a selected one of the process step performance lane and the process step avoidance lane. The item of interest in the sample is determined based upon a reaction between the sample and the reagent.