chemostat A growth chamber that keeps a bacterial culture at a specific volume and rate of growth by limiting nutrient medium and removing
chimera A cell or organism composed of a mixture of genetically different cells; a chimeric antibody is formed by the genetic recombination
of a mouse variable region (for example) and a human constant region. A chimeric molecule is made by combining the DNA from
two different species.
chirality The condition of being chi-ral, that is, a molecule in a configuration that is symmetrical with its mirror image; a right-handed
chiral molecule rotates polarized light rightward, a left-handed chiral molecule rotates polarized light leftward.
Chinese hamster ovary cells; in cell culture, the cells of a female hamster's reproductive organs, which historically have proven to be the basis for good
expression systems in analytical studies and for producing pharmaceutical proteins.
chromatography A technique used to separate molecules based on how they tend to bind to various solids, liquids, and gases; based on the
differential distribution of the substances between a stationary phase (sticky material such as silica gel or silicic acid,
usually contained in a column, tube, or capillary) and a gaseous or liquid mobile phase (a medium that carries the sample
through the stationary phase). This very effective technique can separate substances that are nearly identical.
chromophore A molecule that absorbs UV or visible light.
chromosome A long and complex DNA chain containing the genetic information (genes) of a cell. Prokaryotes contain only a single chromosome;
eukaryotes have more than one, made up of a complex of DNA, RNA, and protein. The exact number of chromosomes is species-specific.
Humans have 23 pairs.
High resolution chromatography available with the Waters UPLC Amino Acid Analysis Solution ensures method robustness with
good quantitation. A short cycle time is possible without compromising accurate results.
chymotrypsin A digestive enzyme that can cleave peptide bonds.
Clean-in-place; a way to clean large vessels (tanks, piping, and associated equipment) without moving them or taking them apart, using a high-pressure
rinsing treatment, sometimes followed by steam-in-place (SIP) sanitization. Chemically cleaning and sterilizing equipment
or systems without removing them from their installed location.
clarify To clear liquid of suspended particles through filtration, extraction/precipitation, or centrifugation.
classical pharmaceuticals Small-molecule, non-biotech drugs produced by chemical synthesis.
clean room A room in which the concentration of airborne particulate matter is controlled at specific limits to facilitate the manufacture
of sterile and high-purity products. Clean rooms are classified according to the number of particles per volume of air to
meet standards of cleanliness. Contaminants on surfaces and people entering and exiting the room also are controlled.
clearance Demonstrated removal of an impurity or potential contaminant from a product.
clinical development The phases of drug development during which a drug is tested in human subjects, also referred to as clinical trials.
clinical endpoint An indicator (such as blood pressure) measured in a human subject to assess the safety, efficacy, or other objective of a
clinical hold Temporary cessation of a clinical trial by FDA if the agency is concerned about a drug or study protocol. The trial may resume
when the problem is solved.
clone To duplicate exactly, whether a gene or a whole organism; or an organism that is a genetically identical copy of another organism.
cloning vectors Methods of transferring desired genes to organisms that will be used to express them. Cloning vectors are used to make recombinant
Carboxymethylcellulose; a weak ion-exchanger that is often coupled to a resin used in charge based separation chromatography. It is a cation exchange