The invention is an improved multiplex capillary electrophoresis instrument or module with at least four and preferably six user-accessible vertically stacked drawers. An x-z stage moves samples from the user accessible drawers to the capillary array for analysis. An additional mechanical stage moves the array from side-to-side. The x-z stage, coupled with the additional array stage allows the system to sample all wells of a 384 well plate with a 96-capillary array. A computer program allows users to add capillary electrophoresis jobs to a queue corresponding to the analysis of rows or plates of samples without stopping or interrupting runs in progress.