Purpose-This core will be used as the diagnostic center for all of the more routine procedures performed in the laboratory. This unit will receive specimens from each of the units and by E-mail daily will feed results to the head of each unit and to the statistics module. Each week an E-mail file will be sent to the JHU. This core thus will serve each of the projects and cores (see Fig). All data will be entered into computerized data sheets and backed up on a daily basis. This core will enable us to be more efficient and eliminate redundant operations by centralizing all diagnostic work in one place. Only specialized or new techniques will be performed in the investigators laboratories. When there are ready they will be transferred to the diagnostic core for implementation. The diagnostic core will be located in the pathology department. All stool and sera specimens will be processed immediately after they have entered from the field.