Comparison of hematocrit determinations by microhematocrit and electronic particle counter

Hematocrit determinations by microhematocrit and electronic particle counter technics were obtained using newborn and adult blood samples. Coulter Model S hematocrit values greater than .47 were found to be significantly lower than those obtained by using the microhematocrit technic. These differences assume clinical importance when considering partial plasma exchange transfusion for the treatment of polycythemia and associated hyperviscosity.