
Abortion
The expulsion of a foetus during gestation before it reaches the stage of independent viability.

Adsorption
The process by which substances or particles accumulate on the surface of a solid object.

Agglutination
The clumping together of cells.

Amino acid sequence
The order (sequence) in which amino acids occur in a protein. The amino acid chain represents the backbone of the protein and is responsible for the macromolecule's internal cohesion and spatial design.

Antigenetic shift
The exchanging of genetic information between different virus types or subtypes with segmented genomes. During replication, individual segments are exchanged between the viruses within a host cell. This leads to the development of new virus variants. These genetic swaps are described as reassortment.

Antigenetic-Drift
Random changes in the surface structures of viruses that prompt an immune response, caused by point mutations in the genome.

Cytopathic
Harmful cell

Cytoplasma
The cell filling basic structure, incl. The whole of the cell organelles and the cell without a nucleus.

ELISA (Enzyme Linked Immuno sorbent Assay)
An antibody-based technique (assay) used to detect antibodies or disease pathogens. Its principle is based on enzymatic colour reactions. The antigen or antibody to be detected is bound using another antibody which is marked with an enzyme.

Endocytosis
The process by which a cell takes in extracellular material by invagination and constriction of parts of its membrane to form spherical cell structures called vesicles.

Erythrocytes
Red blood cells

Gel electrophoresis
A method that separates different types of molecules using an electric field and a gel. Depending on the size and the electric charge of the molecules, they move through the gel towards the two poles at different speeds with the gel acting as a molecular sieve.

Gene pool
The total stock of genetic variation in a population.

Genome
Genetic material. The complete set of genes or hereditary information present in a cell or viral particle.

Genotypes
The genetic constitution of an organism, comprising all of the genes located on the chromosomes. The genotype is often contrasted with the actual physical characteristics, or 'phenotype'.

Haemagglutination inhibition test (HI test)
A method for detecting antibodies, based on their ability to bind the antigen and thus prevent red blood cells from clumping together. Titers can be indicated on the basis of defined concentrations of the test serum.

Heterogeneity
Diversity, non-uniformity.

Histopathology
A branch of pathology concerned with changes in the structure of cells and tissues caused by disease.

Immunoassay
A bioanalytical technique used to detect an antigen or antibody by means of antigen/antibody binding.

Immunofluorescence
A technique used to identify an antigen in cells or body tissues by means of an antigen/antibody binding reaction. It uses antibodies marked with fluorescent dyes which bind to the antigen present in the tissue and can be demonstrated using a particular kind of microscope (fluorescence microscope).

Immunohistochemistry
A method for demonstrating proteins or other structures using labelled antibodies.

Immunostaining
A method for demonstrating proteins with the aid of antibodies.

Incubation period
The time between exposure to infection and the emergence of the first symptoms.

Infection, chain of
The way in which a pathogen is transmitted from host to host. One host is the donor and the other the recipient. Transmission can occur by direct contact, or indirectly, via vectors.

Mutation
A change in the genetic material.

Mutation rate
The number of changes in the genetic material per unit of time.