Staining kinetics in single cells. Part I. Influence of convective diffusion on the staining rate.

The staining kinetics of single cells have been investigated using a perfusion cuvette in combination with a computer controlled microscope spectrometer. The physicochemical hydrodynamics of staining are characterized. Using a steady-state laminar flow parallel to the cell surface a hydrodynamic and a diffusional boundary layer are observed which are determined by the flow rate. The thickness of the diffusional boundary layer revealed by experimental data is in agreement with theoretically calculated values. At certain well-defined hydrodynamic conditions convective diffusion has no further effect on the staining rate.