Flow cytometers (FCM) are used in an estimated 7 of 1000 biomedical research studies and in most clinical laboratories. Automated laser scanning cytometer (LSCM) prototypes having capabilities of an analytical flow cytometer, but which measure cells on slides, not in flow, have been developed and shown feasible for a variety of applications during Phase I. LSCM can complement FCM for applications for which it is impossible to use FCM because cell position is a parameter of LSCM. These are: l) measuring the kinetic properties of individual cells in heterogeneous populations, 2) visualizing or high resolution image analysis of cells with selected biochemical properties, 3) remeasuring cells after restaining or changing excitation wavelength. Additionally, LSCM can use specimens on slides in order to l) select areas that bias against cells of no interest,, 2) use less traumatic preparative techniques such as touch preparations, 3) use techniques like in-situ hybridization, or 4) reduce biological hazards. Phase Il aims are, using a new LSCM instrument, to optimize instrumental and preparation protocols, generate software to easily calibrate, control and provide data and reports of utility, and characterize performance for a variety of applications in order to supply usage packages for each application and to prove LSCM's commercial viability prior to marketing.