Automation in Hematology

electrical impedance principle

This method of cell counting was originally developed by Coulter Electronics and is referred to as the Coulter principle.

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Cell counting and sizing are based on the detection and measurement of changes in electrical impedance (resistance) produced by a particle as it passes through a small aperture.

optical detection principle & flow cytometry

Characteristics of Light Scatter Optical Light Scatter In this category, light amplification is generated by stimulated emission of radiation. Three independent processes are operational. These are:

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1\.Diffraction and the bending of light around corners with the use of small angles

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2\.Refraction and the bending of light because of a change in speed with the use of intermediate angles.

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3\.Reflection and light rays turned back by the surface or an obstruction with the use of large angles

__Forward (angle) light scatter 0°__

This is diffracted light, which relates to the volume of the cell.

__Forward low-angle light scatter 2° to 3°.__

This characteristic can relate to size or volume.

__Forward high angle 5° to 15°__

this type of measurement allows for description of the refractive index of cellular components.

__Orthogonal light scatter 90° (side scatter)__

The result of this application of light scatter is the production of data based on reflection and refraction of internal components, which correlates with internal complexity

RADIOFREQUENCY

In this newer application, high-voltage electromagnetic current is used to detect cell size, based on the cellular density.

nuclear size and density of a cell.

The radio frequency (RF) pulse is directly proportional to the ________

nuclear-cytoplasmic ratio, nuclear density, and cytoplasmic granulation.

RF or conductivity is related to the