The work involves two areas of endeavor, the first is to develop methods for rapidly measuring various parameters of bacterial and mammalian cell growth and the second is to demonstrate the instrumentation methods and techniques and facilitate their use in areas of endeavor not heretofore utilized. Using the capillary tube technique and spatial frequency analysis methods the growth of bacteria, mycoplasma and bone marrow stem cell has been investigated. Capillary flow has also been applied to the study of red blood cell fragility.