G

gas chromatography Analytical method in which a volatile substance to be separated is introduced into a stream of nonreactive gas or other stationary phase. For example, in capillary gas chromatography, the gas mixture moves through a tube coated with liquid, and how fast it moves through the tube depends on the degree to which it stays in the nonreactive gas or dissolves in the liquid (partitioning).

GCP Good clinical practice; according to 21 CFR Parts 56, 312, and 314, the regulations that govern the actions and environment of those working in clinical testing of drugs and medical devices on human beings. These regulations include rules for obtaining informed consent and data integrity requirements.

gene therapy Treats, cures, or prevents disease by changing the expression of a person's genes or inserting genes into the genome. In its infancy, current gene therapy is primarily experimental, with most human clinical trials only in the research stages. Gene therapy can target somatic (body) or germ (egg and sperm) cells. In somatic gene therapy, the recipient's genome is changed, but the change is not passed along to the next generation. In germ-line gene therapy, the parents' egg and sperm cells are changed with the goal of passing on the changes to their offspring.

genetic engineering Altering the genetic structure of an organism (adding foreign genes, removing native genes, or both) through technological means rather than traditional breeding.

genetic polymorphisms Gene alterations, additions, omissions, or deletions that alter biologic functioning or changes in drug metabolism.

genome The collection of all the genes for an organism.

genomics Study of the genetic make-up of organisms, including sequencing and mapping of their DNA. The Human Genome Project was a government-coordinated effort of many genomics researchers who sequenced and mapped the entire human genome.

genotoxicity Ability of a substance to damage the genome.

genotoxin A substance that causes damage to an organism's DNA.

genotype The genetic composition of an organism (including expressed and non-expressed genes), which may not be readily apparent. Compare to phenotype, the outward characteristics that result from gene expression.

germ cell The "sex cells" in higher animals and plants that carry only half of the organism's genetic material and can combine to develop into offspring.

glass state The amorphous solid that, for example, contains the therapeutic protein in lyophilization; any material that takes the shape of its container and is formed by cooling a liquid until it is rigid but not crystallized.

Gin Glutamine; one of more than 20 naturally occurring amino acids.

GLP Good laboratory practices; according to 21 CFR Part 58, regulations to ensure quality of nonclinical laboratory studies related to safety. All activity is recorded, trained staff uses only established procedures, and records and samples are maintained.

Glu Glutamic acid; one of more than 20 naturally occurring amino acids.

glucose A monosaccharide (or simple sugar) is an important carbohydrate in biology. The living cell uses it as a source of energy and metabolic intermediate.

Gly Glycine; one of more than 20 naturally occurring amino acids.

glycan Refers to a polysaccharide or oligosaccharide that can be found attached to proteins as in glycoproteins and proteoglycans.