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Pre-analytical factors affecting the results of laboratory blood analyses in farm animal veterinary diagnostics

Published online by Cambridge University Press:  10 January 2012

E. Humann-Ziehank*
Affiliation:
Division Laboratory Medicine, Clinic for Swine and Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany
M. Ganter
Affiliation:
Division Laboratory Medicine, Clinic for Swine and Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany
*
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Abstract

The quality of the laboratory diagnostic approach in farm animals can be severely affected by pre-analytical factors of variation. They induce increase/decrease of biochemical and hematological analyte concentrations and, as a consequence, they may cause unsuitable conclusions and decisions for animal health management and research projects. The pre-analytical period covers the preparation of sampling, the sampling procedure itself, as well as all specimen handling until the beginning of the specific laboratory analysis. Pre-analytical factors may have either an animal-related or a technique-related background. Animal-related factors cover daytime/season, meals/fasting, age, gender, altitude, drugs/anesthesia, physical exercise/stress or coinfection. Technique-related factors are the choice of the tube including serum v. plasma, effects of anticoagulants/gel separators, the anticoagulant/blood ratio, the blood collection procedure itself, specimen handling, contamination, labeling, storage and serum/plasma separation, transportation of the specimen, as well as sample preparation before analysis in the laboratory. It is essential to have proper knowledge about the importance and source of pre-analytical factors to alter the entire diagnostic process. Utmost efforts should be made to minimize controllable factors. Analytical results have to be evaluated with care considering that pre-analytical factors of variation are possible causes of misinterpretation.

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Copyright © The Animal Consortium 2012

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