Tg

Tg is an abbreviation that can refer to multiple concepts across science and technology. In materials science and polymer chemistry, Tg denotes the glass transition temperature, the temperature range over which an amorphous polymer or glass transitions from a hard, brittle state to a softer, rubbery state. Tg depends on chemical composition, molecular weight, cross-linking, and thermal history and is commonly measured by differential scanning calorimetry (DSC) or dynamic mechanical analysis (DMA).

In biochemistry and food science, transglutaminase (TG or TGase) refers to a family of enzymes that catalyze covalent cross-linking between proteins by forming ε-(γ-glutamyl)lysine bonds. TG2 is well known in biology, while Factor XIIIa is a coagulation factor. Transglutaminases are also used in the food industry as meat glue to improve texture.

In genetics and biomedical research, Tg is used to designate transgenic organisms or transgenic lines, such as Tg mice. These organisms carry inserted foreign DNA to study gene function, regulation, and disease models, often using tissue-specific or inducible promoters.

Other uses exist depending on field, including shorthand in dialogue or literature. The exact meaning of Tg should be inferred from context.