Degree Type


Date of Award


Degree Name

Master of Science


Veterinary Diagnostic and Production Animal Medicine


Veterinary Preventive Medicine

First Advisor

Jeffrey J. Zimmerman


Improvements in swine diagnostic medicine is a never-ending pursuit. However, whereas most researchers focus on assay improvements, this research focused on developing improvements to the sample itself.

The thesis begins with a review of the IgG molecule and the mechanisms and external factors that affect its stability in aqueous solutions. Chapter 2 summarizes the key discoveries that led to an understanding of the structure and functionality of antibodies, the main physicochemical mechanisms and external factors that affect the stability of IgG in aqueous solutions, the implications of IgG stability for diagnostic medicine, and practical recommendations for preserving IgG in diagnostic specimens.

Chapter 3 describes an experiment that evaluated the immediate and temporal effects of chitosan-based clarification treatments on PRRSV ELISA-detectable IgG in swine oral fluids. Serum and OF samples of known status were generated by vaccinating pigs (n = 17) with a PRRSV MLV vaccine. Individual pig oral fluid samples were collected from day post vaccination -7 to 42 and then subdivided into 4 aliquots. Each aliquot was treated with one formulation (A, B, C) with the 4th aliquot serving as untreated control. All samples were tested by PRRSV OF ELISA immediately after treatment (day post-treatment DPT 0). Thereafter, samples were held at 4°C and re-tested on DPTs 2, 4, 6, and 14. Both immediate and temporal treatment effects were evaluated for their quantitative (sample-to-positive ratio) and qualitative (positive vs negative) effects on the PRRSV oral fluid ELISA results. Analysis of results showed that the chitosan-based swine oral fluid clarification formulations evaluated in the study did not affect the stability or diagnostic functionality of PRRSV IgG either immediately after treatment or up to 14 days post-treatment, as measured using PRRSV ELISA S/P results.

Copyright Owner

Yuly Alexandra Henao Diaz



File Format


File Size

57 pages