Characterizing blood cells by biophysical measurements in flow.

One effect of automation in the hematology laboratory has been to introduce new characterizations of blood cells. Resistive pulse sensing (Coulter) and light scatter measurements in flow provide rapid and reproducible cell counts. They also provide information about red cell size, shape, and deformability. Thus, they have provided new characterization of these cells in terms of their biophysical properties. Leukocytes have been classified by optical scatter and absorption measurements in flow after being stained cytochemically. This provides rapid and precise WBC differential counts. However, here again, additional information about relative cell-enzyme content or activity is also accessible to provide a new characterization of the leukocytes. The ultimate range of utility of this expanding technology in the automated hematology laboratory of the future will, of course, depend upon establishing relations between the biophysical parameters and the functions of the cells. This, in turn, must depend upon the use of the technology by researchers and clinicians in studying cell function and the aberrations of these functions which define disease.