An Overview to Development of Hematology Automation

The complete blood count (CBC) test was performed manually until the early 1960s.the manual methods were labor-intensive and involved using of centrifuges, spectrophotometers,counting chambers with etched grids, and stained wedge smears ofblood. Automated methods were gradually replaced the manual methods most diagnosticlaboratories since 1960s. Initial analyzers were essentially less sophisticatedversions of today’s impedance particle counters in which a stream of particles (bloodcells) was sent through an aperture between two electrically charged electrolyte baths.Impedance of the voltage potential between the two baths would register the presenceof each particle as it passed through, and the magnitude of the voltage impedance wasproportional to the volume of the cell, allowing for direct measurement of mean corpuscularvolume (MCV) in red cell populations and discrimination of platelets and othercells based on volume thresholds. Direct measurement of red blood cell volume hasalso allowed for the development of a new basic red cell index, the red cell distributionwidth (RDW).