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Automated Cell-Counting Instrumentation

This document discusses two principles of automated cell counting instrumentation: electronic impedance and optical scatter. Electronic impedance works by measuring changes in electrical resistance as cells pass through a small aperture, generating voltage pulses where each pulse corresponds to a cell. The number of pulses is then displayed on an oscilloscope screen and plotted in a histogram to determine cell counts and size distributions. Optical scatter works by optically scanning or using laser-based optics to measure light scatter from cells.

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Romulo Vincent Perez
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35 views6 pages

Automated Cell-Counting Instrumentation

This document discusses two principles of automated cell counting instrumentation: electronic impedance and optical scatter. Electronic impedance works by measuring changes in electrical resistance as cells pass through a small aperture, generating voltage pulses where each pulse corresponds to a cell. The number of pulses is then displayed on an oscilloscope screen and plotted in a histogram to determine cell counts and size distributions. Optical scatter works by optically scanning or using laser-based optics to measure light scatter from cells.

Uploaded by

Romulo Vincent Perez
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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Automated Cell-Counting

Instrumentation

Principles of operation:
Electronic impedance (resistance)
Low voltage direct current resistance
Coulter (1950s)

Radiofrequency or alternating current resistance

Principles of operation:
Optical scatter (laser and non laser light)
Optical scanning (1960s)
Laser-based optical instrument (1970s)

Electronic Impedance
Based on the detection and measurement of
changes in electrical resistance produced by
cells as they traverse a small aperture
External electrode and internal electrode
Electrical resistance between the 2 electrodes
or impedance in the current, occurs as the
cells pass through the sensing aperture
measurable voltage pulses

Electronic Impedance
Oscilloscope screens display generated pulses
Number of pulses = number of cells
Data plotted on frequency distribution graph
or size distribution histogram

Factors affecting size or volume


measurements
Aperture diameter
Protein buildup decrease diameter of
orifice, slowing the flow of cells, increasing
relative electrical resistance

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