tryptic fragment analysis Quantitating the resultant fragments caused by tryptic digestion.
turbidostat A variation on a chemostat. Whereas a chemostat is designed for constant input of medium, a turbidostat is designed to keep the organisms at a constant concentration. A turbidity sensor measures the concentration of organisms in the culture and adds additional medium when a preset value is exceeded.
turbulent flow field The state that results from mixing the contents of a fermentor or bioreactor to provide oxygen to the cells. That must be balanced against the shear that causes cell damage and death.
unicellular Composed of only a single cell.
vaccines Preparations of antigens from killed or modified organisms that elicit immune response (production of antibodies) to protect a person or ani mal from the disease-causing agent.
vacuolation In cell and tissue culture, excess fluid, debris (aggregates), or gas (from sparging) can form inside a cell vacuole. A vacuole is a cavity within the cell that can be relatively clear and fluid filled, gas filled (as in a number of blue-green algae), or food filled (as in protozoa).
vector The plasmid, virus, or other vehicle used to carry a DNA sequence into the cell of another species.
vessel jacket A temperature control method consisting of a double wall out
side the main vessel wall. Liquid or steam flows through the jacket to heat (or