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Gamete
Mature male or female reproductive cell (sperm or ovum) with a haploid set of chromosomes (23 for humans).

Gamma Globulin
A blood protein that plays a major role in the process of immunity. Sometimes the term "gamma globulin" refers to a whole group of blood proteins that are known as antibodies or immunoglobulins (Ig). Most often, however, it applies to a particular immunoglobulin, designated as IgG, believed to be the most abundant type of antibody in the body.

Gas Metal Arc Welding (GMAW)
An arc welding process that produces coalescence of metals by heating them with an arc between a continuous filler metal (consumable) electrode and the work. Shielding is obtained entirely from an externally supplied gas or gas mixture. Some variations of this process are called MIG (Metal Inert Gas) Or CO2 welding, nonpreferred terms.

Gas Room
A separately ventilated, fully enclosed room in which only toxic and highly toxic compressed gases and associated equipment and supplies are stored or used.

Gas Tungsten Arc Welding (GTAW)
An arc welding process that produces coalescence of metals by heating them with an arc between a tungsten (nonconsumable) electrode and the work. Shielding is obtained from a gas or gas mixture. Pressure may or may not be used and filler material may or may not be used. (This process is sometimes called TIG (Tungsten Inert Gas) welding, a nonpreferred term).

Gel
A colloid, where the dispersed phase is liquid and the dispersion medium is solid.

Gel Electrophoresis
A DNA separation technique that is very important in DNA sequencing. Standard sequencing procedures involve cloning DNA fragments into special sequencing cloning vectors that carry tiny pieces of DNA. The next step is to determine the base sequence of the tiny fragments by a special procedure that generates a series of even tinier DNA fragments that differ in size by only one base. These nested fragments are separated by gel electrophoresis, in which the DNA pieces are added to a gelatinous solution, allowing the fragments to work their way down through the gel. Smaller pieces move faster and will reach the bottom first. Movement through the gel is hastened by applying an electrical field to the gel. (

Gel Polarization
The phenomenon of formation of a layer of insoluble/semi-soluble material at a liquid/filter interface. It is a common occurrence with excessive linear velocity flow through filters of colloidal suspensions and macromolecular solutions.

Gelatin
A derived protein formed from the collagen of the tissues by boiling in water, sometimes called an albuminoid, though it lacks the characteristic albuminoid properties. Glue, size, and isinglass are forms of gelatin.

Gene
A natural unit of hereditary material that is the physical basis for the transmission of the characteristics of living organisms from one generation to another. The basic genetic material is fundamentally the same in all living organisms. It consists of deoxyribonucleic acid (DNA) in most organisms and ribonucleic acid (RNA) in certain viruses, and is usually associated in a linear arrangement that, in part, constitutes the chromosome. The average length of a gene is 1µm and thus, about one million genes could be contained in a one-meter stretch of DNA. The segment of DNA that is involved in producing a polypeptide chain, it includes regions preceding (leader) and following (trailer) the coding region as well as intervening sequences (introns) between individual coding segments (exons).

Gene Expression<
The process by which a gene's coded information is converted into the structures present and operating in the cell. Expressed genes include those that are transcribed into mRNA and then translated into protein and those that are transcribed into RNA but not translated into protein

Gene Family
Group of closely related genes that makes similar products.

Gene Mapping
Determination of the relative positions of genes on a DNA molecule (chromosome or plasmid) and of the distance, in linkage units or physical units, between them.

Gene Markers
Landmarks for a target gene, either detectable traits that are inherited along with the gene, or distinctive segments of DNA.

Gene Product
The biochemical material, either RNA or protein, resulting from expression of a gene. The amount of gene product is used to measure how active a gene is; abnormal amounts can be correlated with disease causing alleles.

Gene Sequencing
The determination of the sequence of bases in a DNA strand. The two most widely used methods are the chain-termination method, developed by Sanger in the mid-seventies, and the chemical method developed by Maxam & Gilbert around the same time.

Gene Splicing
The enzymatic attachment of one gene or part of a gene to another.

Gene Therapy
The insertion of normal DNA directly into cells to correct a generic defect.

Generic Drug
A drug produced and marketed under its chemical or "generic" name (e.g. acetaminophen) as opposed to "Tylenol", a brand name for the former produced by Johnson & Johnson. A generic drug can be sold only after a proprietary drug goes off patent (i.e. when the patent runs out after 17 years). There are numerous generic drug manufacturers. While generic drugs are cheaper for consumers, they still must meet the standards of GMPs as set out by the FDA.

Genetics
The scientific study of heredity: how particular qualities or traits are transmitted from parents to offspring.

Genetic Code
The sequence of nucleotides, coded in triplets (codons) along the mRNA that determines the sequence of amino acids in protein synthesis. The DNA sequence of a gene can be used to predict the mRNA sequence, and the genetic code can in turn be used to predict the amino acid sequence.

Genetic Diseases
Diseases that occur because a mutation in the genetic material.

Genetic Engineering
The selective, deliberate alteration of genes by technological means.

Genetic Engineering Technology


Genetic Map


Genome/B>
The full complement of chromosomes and extra-chromosomal DNA coding for cellular proteins, contained within each cell of a given species. Its size is generally given as total number of base pairs. (also see:
Genome Project
Research and technology development effort aimed at mapping and sequencing some or all of the genome human beings and other organisms.

Genomic Library
A collection of clones made from a set of randomly generated overlapping DNA fragments representing the entire genome of an organism.

Genomic Sequence
The order of the subunits, called bases, that makes up a particular fragment of DNA in a genome. DNA is a long molecule made up of four different kinds of bases, which are abbreviated A, C, T, and G. A DNA fragment that is 10 bases long might have a base sequence of, for example, ATCGTTCCTG. The particular sequence of bases encodes important information in an individual's genetic blueprint, and is unique for each individual (except identical twins).

Genotype
The genetic composition of an organism (including expressed and nonexpressed genes), which may not be readily apparent.

Germicidal Lamps
Light sources that emit ultraviolet radiation at a wavelength of 254 nanometers. These lights are commonly found in biological safety cabinets and used to inactivate bacteria, viruses and fungi which are either airborne or on exposed surfaces.

Germicide
An agent that destroys microorganisms, especially pathogenic microorganisms ("germs"). Sterilants, disinfectants, and antiseptics are germicides.

Germplasm
The total genetic variability, represented by germ cells or seeds, available to a particular population of organisms.

GMP Critical Parameter
A parameter that has a direct effect on product quality.

GMP Facility
A production facility or clinical trial materials pilot plant for the manufacture of pharmaceutical products. It includes the manufacturing space, the storage warehouse for raw and finished product, and support lab areas. A GMP facility operates under the guidelines established by the CFR (Code of Federal Regulations) Title 21, Parts 225 (Current Good Manufacturing for Medicated Feeds - Subpart B), and Part 226 (Current Good Manufacturing Practice for Type A Medicated Articles - Subpart B).

Golgi Bodies
Very small particles composed of membrane aggregates and responsible for the secretion of certain enzymes and macromolecules. Golgi bodies are the deposition and packaging site for many excreted products.

Good Engineering Practice (GEP)
A combination of standards, specifications, codes, regulatory and industrial guidelines as well as accepted engineering and design methods intended to design, construct, operate, and maintain pharmaceutical and/or biotechnology facilities taking into account not only regulatory compliance but also safety, economics, environmental protection and operability. Standards and specifications are provided by recognized sources such as established engineering and architectural contractors as well as pharmaceutical companies. Codes are provided by local, state, or federal jurisdictions and/or insurance companies. Guidelines are issued by professional societies, industrial organizations, or regulatory agencies. Engineering design methods have been established throughout the engineering educational system.

Good Large Scale Practice Organism (GLSP)
The National Institutes of Health (NIH) specifies physical containment levels and defines Biosafety Levels for Large Scale in their "Guidelines for Research Involving Recombinant DNA Molecules" - Appendix K - May 1999. Level of physical containment recommended for large-scale (more than 10 liters of culture) research or production involving viable, non-pathogenic, and non-toxigenic recombinant strains derived from host organisms that have an extended history of safe large scale use. Likewise, the GLSP level of physical containment is recommended for organisms that have a built-in environmental limitation that permits optimum growth in large-scale bioreactors, but limited survival if released to the environment.