This paper describes a fully distributed biological-object system that supports FACS (Fluorescence Activated Cell Sorter) 2 instrumentation. The architecture of the system can be applied to any laboratory automation system that involves distributed instrument control and data management. All component processes of FACS (such as instrument control, protocol design, data analysis, and data visualization), which may run on different machines, are modeled as cooperatively-working "agents." Communication among agents is performed through shared-objects by triggered methods. This shared-object metaphor encapsulates the details of network programming. The system facilitates the annotation of classes with first-order formulae that express logical constraints on objects; these constraints are automatically maintained upon updates. Also, the shared-object communication and polymorphic triggered methods are exploited to produce a homogeneous interface for instrument control.