2D-PAGE
This gel separates proteins on a two-dimensional sheet of gel, first in one direction based on the isoelectric point, then in the other direction based on the molecular weight of the proteins under investigation.
ADMET
absorption, distribution, metabolism, elimination, toxicology
Allele
Short for "allelomorph"; different forms of a gene that can exist at a single locus; the alleles might differ in DNA sequence and also affect the functioning of a single product.
Allele frequency
Describes the commonness of an allele in a given population, i.e. the percentage of all alleles at a given locus in a population gene pool represented by a particular allele.
Amino acid
Building block of proteins; around 20 amino acids are present in proteins: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine.AmpliconA stretch of DNA that has been specifically amplified by PCR
Antibody
An inducible immunoglobulin protein that is produced by the B lymphocytes of the immune system. It recognizes and binds to a specific antigen molecule of a foreign substance introduced into the organism. Upon binding to corresponding antigens, the antibodies set in motion a process to eliminate the antigens.
Antigen
Any foreign substance (self - non-self discrimination), such as virus, bacterium, or protein. After introduction into an organism, the antigenic substances elicit an immune response by stimulating the production of specific antibodies.
Aptamer
DNA or RNA molecule which has been artificially manipulated to allow binding with other molecules and viruses.
Array technology
In a broader context, array technology refers to computer science, engineering and also telecomminications. The technology may involve 2D gel electrophoresis, CCDs, detection technologies, fiber optics, imaging, ink jetting, mass spectrometry, photolithography, phosphorimagers, piezoelectric, semiconductors and spotting robots.
Arrayer
Robot for making microarrays. The robot transfers clones from microwell plates to microscope slides.Association StudyStudy that compares DNA samples from populations of individuals with and without a specific clinical trait
BAC
Stands for Bacterial Artificial Chromosome, a cloning and sequencing vector derived form a bacterial chromosome into which a 100,000 bp fragment or more can be inserted.
BioChip
Miniaturised substrates onto which a large number of biomolecules are attached with high density and in a defined microarray.
Bioinformatics
Science dealing with the classification, storage, retrieval and analysis of genomic and proteomic information; molecular modelling.
Biosensor
Device in which recognition systems of biological chemicals are coupled to microelectronics to allow the low-level detection of substances such as proteins etc. in body fluids or pollutants in water.
Biotinylation
DNA probes are labelled with biotin. Biotinylated triphosphates are incorporated into the molecule by enzyme-dependent labelling reactions such as e.g. nick translation or random primed labelling. Afterwards, the probe is hybridised to the target. The location of biotin is visualised by complexing it with a streptavidin molecule that is attached to a colour-generating agent.
BLAST
Heuristic homology search algorithm
cDNA
Complementary DNA; DNA which is synthesised from a messenger RNA template which is complementary to the coding strand of genomic DNA.
cDNA arrays
Developed at Stanford University; the microarrays are glass slides on which cDNA has been deposited by high-speed robotic printing and suited for expression analysis of up to 10,000 cDNA clones per array from EST sequencing projects. The microarray measurements are carried out as differential hybridisations, namely mRNA from two different sources is labelled with two different fluorescent dyes, then passed over the array at the same time. The fluorescence signal from each mRNA population is evaluated independently to calculate the treated or control expression ratio.
Cell array
High-throughput characterisation of gene function using cell arrays. High-density ordered array involving either living cells (microwells) or printed microarrays (slides). The latter involve full-length open reading frames of the genes in expression vectors that are printed at high density on a slide along with a transfection reagent. The slide is then placed in a cell culture plate and the microarray of DNA constructs is covered with adherent cells. Cells grow on top of the DNA spots, are transfected, and drive the expression of specific proteins.
Chromosome
Threadlike component in the cell which contains DNA and proteins. Humans have 23 pairs of chromosomes --> 46 chromosomes
Clone
A group of genes, cells or organisms that are derived from a common ancestor. Genetic material is not combined and the members of the clone therefore all genetically identical to the parent.
Codon
Sequence of three nucleotide bases that specifies a certain amino acid or a stop or start codon.
DNA
Deoxyribonucleic acid consists of a polysugar-phosphate backbone from which the purines and pyrimidines project. The backbone is formed by bonds between the phosphate molecule and carbon 3 and 5 of the adjacent deoxyribose molecules. The nitrogenous base extends from carbon 1 of each sugar. It forms a double helix hold together by hydrogen bonds between specific pairs of bases (Watson-Crick model) and each strand in the double helix is complementary to its partner with regard to its base sequence. See also: DNA array, DNA chip, DNA microarray
DNA array
DNA arrays consist of large numbers of DNA molecules spotted in a systematic order on a solid substrate. Depending on the spotting technique used, the number of spots can range from hundreds to thousands. See also: DNA, DNA chip, DNA microarray
DNA chip
These chips are also referred to as DNA arrays, or microarrays. Approx. 10,000 cDNAs can be spotted onto a microscope slide and subsequently be hybridised with a double-labelled probe. See also: DNA, DNA array, DNA microarray
DNA microarray
This kind of microarray consists of a set of regular arranged spots of DNA recognition elements (e.g. oligos) positioned on a rigid support. The diameters of the spots range between 20 and 200 micrometers. Usually 50 to 80,000 spots cover an area of approximately 1 square centimetre. The technology is based on the selective recognition of gene sequences by hybridisation, namely the base-pairing of the 4 nucleotides. Upon hybridisation with e.g. a fluorescently-labelled sample (oligo, cDNA, mRNA, PCR product) the signals can be analysed. See also: DNA, DNA array, DNA chip