Glossary

  • Active immunity

    A type of acquired immunity whereby resistance to a disease is built up by either having the disease or receiving a vaccine to it.
  • Adjuvant

    Insoluble material that increases the formation and persistence of antibodies when injected with an antigen.
  • Allele

    Any of several alternative forms of a gene.
  • Allogenic

    Of the same species, but with different genotype.
  • Alzheimer's disease

    Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive deterioration together with declining activities of daily living and neuropsychiatric symptoms or behavioral changes. It is the most common cause of dementia.
  • Amino acids

    Building blocks of proteins. There are 20 common amino acids used to construct proteins.
  • Amplification

    The process of increasing the number of copies of a particular gene or chromosomal sequence
  • Antibody (cellular)

    An antibody which has the ability to attach itself onto the membrane of certain cells, a property which gives these cells a specific activity against an antigen.
  • Anticodon

    Triplet of nucleotide bases (codon) in transfer RNA that pairs with (is complementary to) a triplet in messenger RNA.
  • Bacteriophage

    Virus that lives in and kills bacteria. Also called phage.
  • Bacterium

    Any of a large group of microscopic organisms with a very simple cell structure. Some manufacture their own food, some live as parasites on other organisms and some live on decaying matter.
  • Base pair

    Two nucleotide bases on different strands of the nucleic acid molecule that bond together. The bases can pair in only one way: adenine with thymine (DNA) or uracil (RNA) and guanine with cytosine.
  • Base

    On the DNA molecule, one of the four chemical units that, according to their order and pairing , represent the different amino acids. The four bases are: adenine (A), cytosine ( C), guanine (G) and thymine (T). In RNA, uracil (U) substitutes for thymine.
  • Biocatalyst

    In bioprocessing, an enzyme that activates or speeds up a biochemical reaction.
  • Biochip

    An electronic device that uses organic molecules to form a semiconductor.
  • Bioconversion

    Chemical restructuring of raw materials by using a biocatalyst.
  • Bioinformatics

    A science that uses advanced computing techniques for management and analysis of biological data. Bioinformatics is particularly important as an adjunct to genomic research, which generates a large amount of complex data, involving DNA sequences and hundreds of thousands of genes.
  • Biolistic device

    Shooting microscopic DNA-coated particles into target cells.
  • Bioreactor

    Vessel used for bioprocessing: cultivation of cells under controlled conditions.
  • Candidate gene

    A gene whose function or location suggests that it may be responsible for a disease or trait in a population of individuals.
  • Catalyst

    An agent (such as an enzyme or a metallic complex) that facilitates a reaction but is not itself changed during the reaction.
  • Cell bank

    A uniform pool of cells, distributed into vials and preserved, typically by freezing in liquid nitrogen. A viral is thawed to start each new production cycle.
  • Cell line

    Cells which result from the subcultivations of primacy cell cultures.
  • Cell-mediated immunity

    Acquired immunity in which T lymphocytes play a predominant role. Development of the thymus in early life is critical to the proper development and functioning of cell-mediated immunity.
  • Cell

    The smallest structural unit of living organisms that is able to grow and reproduce independently.
  • Chimera

    The individual (animal or lower organism) produced by grafting an embryonic part of one species onto an embryo of either the same or a different specie.
  • Chromosomes

    Threadlike components in the cell that contain DNA and proteins. Genes are carried on the chromosomes.
  • Clone

    A term that is applied to genes, cells or entire organisms that are derived from -and are genetically identical to - a single common ancestor gene, cell or organism, respectively.
  • Codon

    A sequence of three nucleotide bases that specifies an amino acid or represents a signal to stop or start a function.
  • Complementary DNA

    DNA synthetised from a messenger RNA. This type of DNA is used for cloning or as a DNA probe for locating specific genes in DNA hybridisation studies.
  • Continuous cell-line

    A cell line which has acquired the characteristic of being “immortal”, i.e. capable of growing indefinitely in culture.
  • Crossing-over

    Exchange of genes between two paired chromosomes.
  • Culture

    As a noun, cultivation of living organisms in prepared medium; as a verb, to grow in prepared medium.
  • Cytogenetics

    Study of the cell and its heredity-related components, especially chromosomes.
  • Cytoplasm

    Cellular material that is within the cell membrane and surrounds the nucleus.
  • Cytotoxic

    Able to cause cell death
  • Deoxyribonucleic acid (DNA)

    The molecule that carries the genetic information for most living systems. The DNA molecule consists of four bases and a sugar-phosphate backbone, arranged in two connected strands to form a double helix.
  • Differential gene expression (DGE)

    A laboratory technique that compares the body of expressed (switched on) genes in different cells under different conditions by measuring the mRNA in a diseased liver cell with that in a healthy liver cell.
  • Differentiation

    The process of biochemical and structural changes by which cells become specialised in form and function.
  • Diploid

    A cell with two complete sets of chromosomes
  • DNA sequence

    The order of nucleotide bases in the DNA molecule.
  • Embryo

    Term used to describe the early stages of foetal growth, from conception to the eight week of pregnancy.
  • Enzyme

    A protein catalyst that facilitates specific chemical or metabolic reactions necessary for cell growth and reproduction.
  • Escherichia coli (E. coli)

    A bacterium that inhabits the intestinal tract of most vertebrates. Much of the work using recombinant DNA techniques has been carried out with this organism because it has been genetically well characterised.
  • Eukaryote

    A cell or organism containing a true nucleus, with a well-defined membrane surrounding the nucleus. All organisms except bacteria, viruses and blue-green algae are eukaryotic.
  • Exon

    In eukaryotic cells, that part of the gene that is transcribed into messenger RNA and encodes a protein.
  • Expressed sequence tags (EST)

    Partial gene sequences
  • Expression

    Gene expression, the process of transferring the information encoded in the gene to a functional product e.g. a protein.
  • Gene mapping

    Determination of the relative locations of genes on a chromosome.
  • Gene sequencing

    Determination of the sequence of nucleotide bases in a strand of DNA.
  • Gene therapy

    The replacement of a defective gene in an organism suffering from a genetic disease. Recombinant DNA techniques are used to isolate the functioning gene and insert it into cells. Over 300 single-gene genetic disorders have been identified in humans. A significant percentage of these may be amenable to gene therapy.
  • Gene

    A segment of chromosomes. Some genes direct the syntheses of proteins, while others have regulatory functions.
  • Genetic code

    The mechanism by which genetic information is stored in living organisms. The code uses sets of three nucleotide bases (codons) to make the amino acids that, in turn, constitute proteins.
  • Genetic screening

    The use of a specific biological test to screen for inherited diseases or medical conditions. Testing can be conducted prenatally to check for metabolic defects and congenital disorders in the developing foetus as well as postnatally to screen for carriers of heritable diseases.

  • Genetic testing

    The analysis of an individual’s genetic material. Genetic testing can be used to gather information on an individual’s genetic predisposition to a particular health condition, or to confirm a diagnosis in genetic disease.
  • Genetic

    A technology used to alter the genetic material of living modification cells in order to make them capable of producing new substances or performing new functions.
  • Genetics

    The study of traits passed on from parent to child and variation of those traits within and between individuals.
  • Genome

    The total hereditary material of a cell, comprising the entire chromosomal set found in each nucleus of a given species.
  • Genotype

    The type of gene or genetic marker an individual has at a specific location in his or her genome. A genotype consists of 2 alleles since chromosomes come in pairs. However, a genotype on either of the male sex chromosomes (X or Y) consists of a single allele.
  • Granulocytes

    One of three types of white blood cells. Granulocytes digest bacteria and other parasites.
  • Haploid

    A cell with half the usual number of chromosomes, or only one chromosome set. Sex cells are haploid.
  • Haplotype

    A series of alleles found at linked loci on a single chromosome.
  • Hapten

    The portion of an antigen that determines its immunological specificity. When coupled to a large protein, a hapten stimulates the formation of antibodies to the two-molecules complex. Also called antigenic determinant.
  • Heredity

    Transfer of genetic information from parent cells to progeny
  • Histocompatibility antigen

    An antigen that causes the rejection of grafted material from an animal different in genotype from the host animal
  • Hormone

    A chemical or protein that acts as a messenger or stimulatory signal, relaying instructions to stop or start certain physiological activities. Hormones are synthesised in one type of cell and then released to direct the function of other cell types.
  • Host-vector system

    Combination of DNA-receiving cells (host) and DNA-transporting substance (vector) used for introducing foreign DNA into a cell.
  • Host

    A cell or organism used for growth of a virus, plasmid or other form of foreign DNA, or for the production of cloned substances.
  • Hybridisation

    Production of offspring, or hybrids, from genetically dissimilar parents. The term is also used to refer to the binding of complementary strands of DNA or RNA.
  • Hybridoma

    The cell produced by fusing two cells of different origin. In monoclonal antibody technology, hybridomas are formed by fusing an immortal cell (one that divides continuously) and an antibody-producing cell.
  • Immune response

    The response of the immune system to challenge by a foreign antigen.
  • Immune serum

    Blood serum containing antibodies.
  • Immune system

    The aggregation of cells, biological substances (such as antibodies) and cellular activities that work together to provide resistance to disease.
  • Immunity

    Nonsusceptibility to a disease or to the toxic effects of antigenic material.
  • Immunoglobulin

    General name for proteins that function as antibodies. These proteins differ somewhat in structure and are grouped into five categories on the basis of these differences.
  • Immunology

    Study of all phenomena related to the body’s response to antigenic challenge.
  • In situ

    In its original or natural place or position
  • In vitro

    Literally, in “glass”. Performed in a test tube or other laboratory apparatus.
  • In vivo

    In the living organism.
  • Interferon

    A class of lymphokine proteins important in the immune response. There are 3 major types of interferon: alpha, beta, gamma. Interferons inhibit viral infections and may have anticancer properties.
  • Interleukin

    A type of lymphokine that regulates the growth and development of white blood cells. 12 interleukins have been identified to date.
  • Intron

    In eukaryotic cells, a sequence of DNA that is contained in the gene but does not encode for protein. The presence of introns “splits” the coding region of the gene into segments called exons.
  • Isogenic

    Of the same genotype
  • Leukocyte

    A colourless cell in the blood, lymph and tissues that is an important component of the body’s immune system.
  • Library

    A set of cloned DNA fragments.
  • Ligase

    An enzyme used to join DNA or RNA segments together. They are called DNA ligase or RNA ligase, respectively.
  • Linker

    A fragment of DNA with a restriction site that can be used to join DNA strands.
  • Lymphocyte

    A type of leukocyte found in lymphoblastic tissue in the blood, lymph nodes and organs. Lymphocytes are continuously made in the bone marrow and mature into antibody-forming cells. Lymphocyte T : Their maturation is controlled by the thymus. They are thymus-dependent and can be “helper” or “killer”. They are the keepers of immunological memory. Lymphocyte B : Bone marrow-derived antibody producing immunoglobulin after maturation.
  • Lymphokine

    A class of soluble proteins produced by white blood cells that play a role, as yet not fully understood, in the immune response.
  • Macrophage

    A type of white blood cell produced in blood vessels and loose connective tissues that can ingest dead tissues and cells and is involved in producing interleukin.
  • Medium

    A substance containing nutrients needed for cell growth.
  • Medium

    A substance containing nutrients needed for cell growth.
  • Meiosis

    Process of cell reproduction whereby the daughter cells have half the chromosome number of the parent cells. Sex cells are formed by meiosis.
  • Messenger RNA (mRNA)

    Nucleic acid that carries instructions to a ribosome for the synthesis of a particular protein.
  • Microinjection

    The injection of DNA using a very thin needle into a cell.
  • Microorganism

    Any organism that can be seen only with the aid of a microscope.
  • Mitosis

    Process of cell reproduction whereby the daughter cells are identical in chromosome number to the parent cells.
  • Molecular genetics

    Study of how genes function to control cellular activities.
  • Monoclonal antibody (Mab)

    Highly specific, purified antibody that is derived from only one clone of cells and recognises only one antigen.
  • Monocytes

    One of three types of white blood cells. Monocytes are precursors to macrophages.
  • Mutant

    A cell that manifests new characteristics due to a change in its DNA.
  • Natural active immunity

    Immunity that is established after the occurrence of a disease.
  • Natural killer cell (NK)

    A type of leukocyte that attacks cancerous or virus-infected cells without previous exposure to the antigen. NK cell activity is stimulated by interferon.
  • Natural passive immunity

    Immunity conferred by the mother on the foetus or new-born.
  • Nucleic acid

    Large molecules, generally found in the cell’s nucleus and/or cytoplasm, that are made up of  nucleotide bases. The two kinds of nucleic acid are DNA and RNA.

  • Nucleotides

    The building blocks of nucleic acids. Each nucleotide is composed of sugar, phosphate and one of four bases. The sequence of the base within the nucleic acid determines what proteins are made.
  • Nucleus

    The structure within eukaryotic cells that contains chromosomal DNA.
  • Oligonucleotide

    A polymer consisting of a small number (about two to ten) of nucleotides.
  • Oncology

    Study of tumours.
  • Oncology

    Study of tumours.
  • Operator gene

    A region of the chromosome, adjacent to the operon, where a repressor protein binds to prevent transcription of the operon.
  • Operon

    Sequence of genes responsible for synthesising the enzymes needed for biosynthesis of a molecule. An operon is controlled by an operator gene and a repressor gene.
  • Osteoporosis

    Osteoporosis is a disease of bone in which the bone mineral density (BMD) is reduced, bone microarchitecture is disrupted, and the amount and variety of non-collagenous proteins in bone is changed. Osteoporotic bones are more susceptible to fracture. Osteoporosis is defined by the World Health Organization (WHO) as either a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old person standard) as measured by DXA, or any fragility fracture. While treatment modalities are becoming available, prevention is still the most important way to reduce fracture. Due to its hormonal component, more women, particularly after menopause, suffer from osteoporosis than men.
  • Parkinson's disease

    Parkinson's disease (also known as Parkinson disease or PD) is a degenerative disorder of the central nervous system that affects the control of muscles, and so may affect movement, speech and posture. Parkinson's disease belongs to a group of conditions called movement disorders. It is often characterized by muscle rigidity, tremor, a slowing of physical movement (bradykinesia), and in extreme cases, a loss of physical movement (akinesia). The primary symptoms are the results of excessive muscle contraction, normally caused by the insufficient formation and action of dopamine, which is produced in the dopaminergic neurons of the brain. Secondary symptoms may include high level cognitive dysfunction and subtle language problems. PD is both chronic, meaning it persists over a long period of time, and progressive.
  • Passive immunity

    Immunity acquired from receiving pre-formed antibodies.
  • Peptide

    Two or more amino acids joined by a linkage called a peptide bond.
  • Phagocyte

    A type of white blood cell that can ingest invading microorganisms and other foreign material.
  • Pharmacogenetics

    Study of the DNA sequence variation as it relates to differential drug response.
  • Pharmacogenomics

    In its broader sense, it can be defined as the study of the genome and its products (including RNA and protein) as they relate to drug discovery and development.
  • Phenotype

    Observable characteristics resulting from interaction between an organism’s genetic makeup and the environment.
  • Plasmid

    A small circular form of DNA that carries certain genes and is capable of replicating independently in a host cell.
  • Plasmocyte

    Lymphoid cell which synthesised and secretes immunoglobulins. They are deriving from the maturation of Lymphocytes B.
  • Polyclonal

    Derived from different types of cells.
  • Zygote

    A fertilised oocyte (first stage of embryo development).
  • Polymerase chain reaction (PCR)

    A method for repeatedly duplicating trace amounts of DNA in order to provide detectable quantities for analysis. PCR is frequently used for DNA fingerprinting (DNA profiling).
  • Polymorphism

    The existence of two or more variants (alleles, phenotypes, DNA sequence variants, chromosomal structure variants) at significant frequencies in the population.
  • Wild type

    The form of an organism that occurs most frequently in nature.
  • Tissue culture

    In vitro growth in nutrient medium of cells isolated from tissue.
  • Transcription

    Synthesis of messenger(or any other) RNA on a DNA template.
  • Transduction

    Transfer of genetic material from one cell to another by means of a virus or phage vector.
  • Transfection

    Infection of a cell with nucleic acid from a virus, resulting in replication of the complete virus.
  • Transfer RNA (tRNA)

    RNA molecules that carry amino acids to sites on ribosomes where proteins are synthesised.
  • Polypeptide

    Long chain of amino acids joined by peptide bonds.
  • Transformation

    Change in the genetic structure of an organism by the incorporation of foreign DNA.
  • Post-traductionnal modification

    Modification of a protein after it has been synthesised via mRNA.
  • Transgenic organism

    An organism formed by the insertion of foreign genetic material into the germ line cells of organisms. Recombinant DNA techniques are commonly used to produce transgenic organisms.
  • Prokaryote

    An organism whose DNA is not enclosed within a nuclear membrane.
  • Promoter

    A DNA sequence that is located in front of a gene and controls gene expression. Promoters are required for binding RNA polymerase to initiate transcription.
  • Translation

    Process by which the information on a mRNA molecule is used to direct the synthesis of a protein.
  • Prophage

    Phage nucleic acid that is incorporated into the host’s chromosome but does not cause cell lysis.
  • Transposon

    A segment of DNA that can move around and be inserted at several sites in bacterial DNA or in a phage, thus alerting the host’s DNA.
  • Protein

    A molecule composed of amino acids. There are many types of proteins, all carrying out a number of different function essential for cell growth.
  • Sequencing

    Decoding a strand of DNA or gene into the specific order of its nucleotides. This analysis can be done manually or with automated equipment.
  • Receptors

    Cells or group of cells whose main function is the detection of certain stimuli.
  • Recombinant DNA (rDNA)

    The DNA formed by combining segments of DNA from different types of organisms.
  • Single-nucleotide polymorphism (SNP)

    An SNP is a single base variation that occurs about every 1000 bases along 3 billion base pairs of the human genome.
  • Replication

    Reproduction or duplication, as of an exact copy of a strand of DNA.
  • Somatic cell gene therapy

    Involves the insertion of genes into somatic cells for therapeutic purposes.
  • Replicon

    A segment of DNA that can replicate independently
  • Retrovirus

    A virus that contains the enzyme reverse transcriptase. This enzyme converts the viral RNA into DNA, which can combine with the DNA of the host cell and produce more viral particles.
  • Ribonucleic acid (RNA)

    Nucleic acid coming from the transcription of the DNA.
  • Somatic cells

    Cells other than sex or germ cells.
  • Splicing

    The removal of introns and joining of exons to form a continuous coding sequence in RNA.
  • Structural gene

    A gene that codes for a protein, such as an enzyme.
  • Suppressor gene

    A gene that can reverse the effect of a mutation in other genes.