Hematology Unit 2 Chapter 8 Automated Analyzers Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved.

Automated Analyzers Cost effective and convenient Several CBCs performed daily Benefits Reduced labor costs More complete information Improved data reliability Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 2

Automated Analyzers (cont.) Cell counts RBCs WBCs Platelets Manual cell count methods not routinely performed Avian and exotic practices Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 3

Polycythemia a.k.a. erythrocytosis Increased number of RBCs Accompanied by increased PCV and hemoglobin concentration Result of primary or secondary pathology or relative polycythemia Relative polycythemia – splenic contraction or dehydration Primary polycythemia - myeloproliferative disorders Secondary polycythemia – renal and lung disorders Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 4

Impedance Analyzers Passage of electric current across two electrodes separated by a glass tube with a small opening or aperture Electrolyte fluid conducts the current Counting by moving a specific volume of cells in the electrolyte solution through the aperture by use of a vacuum or positive pressure Cells are poor conductors and impede the flow of the current Cell size based on change in current Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 5

Impedance Analyzers (cont.) Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 6

Impedance Analyzers (cont.) Disadvantages Variation of cell size Morphologic abnormalities not noted Contaminates disrupt results Platelet clumping inaccuracies Nucleated RBC inaccuracies Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 7

Quantitative Buffy Coat Analysis System Uses differential centrifugation and staining to estimate cells Uses specialized microhematocrit tube Gives hematocrit value and estimates WBC and platelet concentrations Limitation Left shift may go undetected Provides only estimates Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 8

Laser-based Flow Cytometer Analyzers Uses focused laser beams to evaluate the size and density Cells scatter light differently Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 9

Histograms Offered by many automated analyzers Can provide evidence of anomalies Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 10

Manual Cell Counts Counting of RBCs and WBCs Rarely performed with manual methods Except in avian and exotic animal practice Exotic animal counts require a Leukopet system Hemocytometer Counting chambers determine cells per microliter of blood Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 11

Summary Impedance analyzers Quantitative buffy coat analyzers Laser-based flow cytometer analyzers Histograms Manual cell counts Copyright © 2015 by Mosby, an imprint of Elsevier Inc. All rights reserved. 12