Post-mortem investigations yield clues to the cause of death. We look for abnormalities that may indicate infection or disease and collect tissue samples for further analysis.
Microscopic study of cells and tissue is conducted using thin slices of tissue sections mounted on slides. Dissected tissues are excised from animals and preserved in a formalin fixative. The tissue sections are then embedded in paraffin wax, sectioned, stained, and viewed under a microscope.
Our laboratory utilizes several very sensitive methods to detect pathogens by probing for their DNA rather than visualizing the organisms themselves. Gene sequences unique to suspected pathogens can be used to determine their presence through such methods as the polymerase chain reaction (PCR) and in situ hybridization. We also sequence purified DNA segments to confirm identity.
When a bacterial or fungal infection is suspected as the cause of disease, samples of lesions, blood, and shell are cultured on selective, non-selective, and differential media to propagate the pathogen and determine its identity.