Microscope Requirements

When examining a peripheral blood smear, a hematologist starts with a low magnification objective, typically a 20x or 10x. The hematologist gets an overview of red and white blood cell densities, the amount of erythrocytes, its color and rough morphology and if obvious cellular inclusions are present. In higher magnification (typically 60x or 100x, sometimes 40x for bone marrow), a manual differential cell count is performed and red and white blood cell morphology including the presence of inclusions or parasites are assessed. A very good differentiation of cell types and clearly visible cellular details are absolute prerequisites in hematology. Hematologists rely on crystal-clear images to visualize morphological details such as delicate granules, Auer rods, irregularities of the nuclear membrane or clefted nuclei.

Furthermore, highest color fidelity is key when examining blood smears and bone marrow preparations. Apart from brightfield microscopy phase contrast and polarizing microscopy techniques are also used for certain types of samples. While hematological stains result in a good transparency of the sample and specific staining of cellular features, it is the optical quality of the microscope, the fidelity of the attached camera for digital documentation, and the ergonomic design of the instrument that can make all the difference when screening patient samples.