An automated immunoassay analyzer includes a computer controlled instrument (10) and display (16). The display (16) provides a real-time presentation of all operations being performed within the instrument (10). A large number of samples can be loaded into the instrument (10), and the order of testing the samples can be rearranged according to a priority determined by the operator at any time. A wide variety of immunoassays can be performed on each sample and several different immunoassays can be performed on any one sample. Information related to the type of immunoassays being performed on particular samples is collected by a bar code reader (44) and this information is conveyed to the computer (12) for presentation on the display (16). The computer (12) tracks the progress of each immunoassay through the reaction circuit to the detection station (46). The time to completion for particular immunoassays as well as the concentration information for recently completed immunoassays is provided in a readily usable format. The immunoassay automation process is improved by performing the washing operation with an assay tube (26) which allows water to be expelled by centrifugal forces generated by rotating the tube about its longitudinal axis; rather, than by using more conventional aspirating equipment. Bound label is detected by chemiluminescence using a photomultiplier tube (96).