Methods of laboratory research in veterinary medicine

Thanks to the latest high-tech equipment and reagents, laboratory diagnostics is able to provide both common and rarest analyzes, and obtain high-quality and most informative data on the processes occurring in the body in the shortest possible time.

For example, laboratory tests such as blood tests (biochemical, hematological), serological, parasitological, bacteriological, ELISA, PCR are carried out in the Laboratory for the diagnosis of ASF ( African swine fever ) and other especially dangerous animal diseases of the Federal State Budgetary Institution "Rostov Reference Center of Rosselkhoznadzor" for the diagnosis infectious diseases in animals.

Often used immunological research methods based on the formation of specific immune complexes from antigens and antibodies. Using specific reactions, the presence and titers of antibodies to leptospirosis and other infections are often determined, making it possible to assess the body's resistance to various infectious diseases and predict the development of these diseases, as well as evaluate the effectiveness of vaccination .

The most common laboratory diagnostic service in veterinary medicine is a blood test, which helps to determine changes in the general condition of the animal and the functional characteristics of most organs and systems.

A general clinical blood test allows you to diagnose most blood diseases (anemia, leukemia, etc.).

A clinical blood test is carried out on hematological analyzers or manually (Goryaev's chamber) in order to count blood cells (leukocytes, erythrocytes, platelets), as well as assess their size, structure and cytochemical characteristics of cells, hemoglobin concentration.

To perform biochemical analysis, special automatic biochemical analyzers are used, the principle of operation of which is based on various research methods, mainly optical.

Currently, immunological methods such as enzyme-linked immunosorbent assay (ELISA) and immunochromatography (IC) are widely used in veterinary medicine, which allow detecting antibodies to certain viruses in blood serum, or antigens in the test sample.

Bacteriological diagnostics begins with the collection, preservation and transportation of pathological material and includes three stages of research:

1. Microscopic studies of the source material make it possible to detect the presence of a pathogen in it, to study its morphological features and tinctorial properties.

2. Bacteriological studies are carried out in order to isolate a pure culture of the pathogen with the establishment of its morphological, tinctorial, cultural and biochemical properties, and in some cases - antigenic structure.

3. Biological studies (setting up a bioassay) are carried out by infecting laboratory animals, which make it possible to determine the virulence of the pathogen, as well as to isolate it in a pure culture.

The conducted studies allow us to determine the species of the pathogen and make a bacteriological diagnosis.

Despite the variety of methods for laboratory diagnosis of infectious diseases, the most modern and accurate is real-time polymerase chain reaction (PCR).

The real-time PCR method (PCR - real time) is based on the principle of natural replication of nucleic acids, which allows to achieve a significant increase in low concentrations of certain DNA fragments in a biological sample. The PCR process consists of a series of cyclically repeated reactions: DNA denaturation, probe annealing, and DNA synthesis (elongation). The absence of an electrophoresis step allows minimizing the risk of contamination with PCR products and, thus, dramatically reducing the number of false positive results, since registration of results is carried out directly in the process of polymerase chain reaction.