Automated Instrumentation

Front 1

Coulter principle

Back 1

• passage of each cell through the aperture creates an electrical pulse which appears as a spike on the oscilloscope screen
  
• The height of each spike is proportional to the size of the cell.
  

Front 2

Threshold and channels

Back 2

• To choose a pulse size we use an electronically set size limit called a Threshold.
  
• We can use a series of thresholds to sort cells of a population into many subgroups by size. The area between thresholds is a Channel
  

Front 3

Aperture Impedance

Back 3

System uses Sweep Flow

• Eliminates recirculation of cells
  
• Cells pushed away from critical (counting) zone by diluent
  
• More accurate counts
  

Front 4

Normal RBC histogram

Back 4

• Most RBCs fall between 80 and 100 fl.
  
• histogram should start at the baseline on the left and a small “tail” may be evident on the right = doublets and triplets (cells that go through the aperture in twos and threes).
• These are excluded from the RBC MCV by algorithms but may be seen on the histogram.
  

Front 5

Back 5

normal RBC

Front 6

Back 6

Normal platelet histogram

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Back 7

abnormal platelets - large platelets

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Back 8

abnormal platelets - small platelets

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Back 9

Front 10

Back 10

ImmNE1 & ImmNE

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Back 11

lymphocytosis

Front 12

Back 12

reactive lymphs

Front 13

Back 13

eosinophilia

Front 14

Flow Cytometry

Back 14

• Technique for counting, examining and sorting microscopic particles suspended in a stream of fluid.
  
• It allows simultaneous multiparametric analysis of the physical and/or chemical characteristics
  

Front 15

Examples of parameters in flow cytometry

Back 15

• VOLUME = SIZE
  
• CONDUCTIVITY = INTERNAL COMPOSITION
  
• LIGHT SCATTER = CELL SHAPE / SURFACE
  

Front 16

Flow cytometry - volume

Back 16

• Measures Total Cell Volume (size)
  
• Direct Current Impedance
  

Front 17

Flow cytometry - conductivity

Back 17

• Measures Internal Cell Structures such as nucleus and granules
  
• radiowaves or other high wave frequencies
  

Front 18

flow cytometry - light scatter

Back 18

Measures Cell Surface Granularity Using a Broad Range of Angles.

Front 19

Sysmex system

Back 19

Direct current (Impedance) technology with hydrodynamic focusing

Fluorescent flow cytometery:

• Fluorescent stain – nucleic acid and cytoplasmic organelles
  
• Measures fluorescence and side angle light scatter to differentiate cells
  

Front 20

Sysmex WBC measurements

Back 20

Measures:

• forward scatter (SIZE)
  
• side scatter (internal composition)
  
• side fluorescence of the WBC populations (additional info on granularity and size)
  

Front 21

Mean platelet volume

Back 21

7.5-11.5 fL

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Back 22

abn rbc - cold agglutinins

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Back 23

abn rbc- macrocytic

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Back 24

abn rbc - does not start at baseline

could be schistos, micro, nrbcs, giant plts

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Back 25

abn rbc - two cell populations

transfusion