Procedures for the Automation of the White Blood Cell Differential Count

The complete clinical examination of a blood sample comprises a number of tests of which one is the white blood cell differential count. This test consists of examining a suitably prepared blood smear under the microscope to establish the percentage of occurrence of the five normal types of white cell and to see whether any abnormal or immature cells are present. Typical values would be: Neutrophils (including band cells) 65% Lymphocytes 27% Monocytes 5% Eosinophils 2% Basophils 1% A complete description of the various hematological tests has been given by Wintrobe (cf (11)).