C

cake The solid sediment that has been compacted in a centrifuge after removal of as much liquid as possible; or the remaining solid after completion of a lyophilization.

calorimetry Analytical method that measures heat loss or gain resulting from physical or chemical changes in a sample. Differential scanning calorimetry compares the results of heating a sample to those for heating a reference material—for example, to measure the temperature at which the sample crystallizes, changes phase, or decomposes.

CAPA Corrective and preventive action; a quality system defined by 21CFR820.100; the policies, procedures, and support systems that enable a firm to assure that exceptions are followed up with appropriate actions to correct the situation, and with continuous improvement tasks to prevent recurrence and eliminate the cause of potential nonconforming product and other quality problems. [From FDAQSG]

capillary electrophoresis The miniaturized instrumental version of traditional electrophoresis using capillary column technology (that is, tiny fused-silica tubes with 20 to 100 μm inner diameters) and light-absorbance or fluorescence detection.

capsid The outer protein shell of a virus particle (virion).

carbohydrates Molecules consisting of sugars. The basic carbohydrate units are called monosaccharides, such as glucose, galactose, and fructose. Monosaccharides can be linked together into what are called polysaccharides (or oligosaccharides) in almost limitless ways. Oligosaccharides contain a small number (typically three to 10) of component sugars.

carbonyl bond An oxygen atom double-bonded to a carbon atom; the carbon atom then has two additional bonds to attach to the rest of the molecule.

carcinogenic Cancer-causing; many agents that are carcinogenic are mutagens (agents that increase the occurrence of mutation).

cascade effects A series of events that result from one initial cause.

catabolites Waste products of catabolism, by which organisms convert substances into excreted compounds.

cation A positively charged ion (having fewer electrons than protons).

CBE Changes being effected; a regulatory submission sent to FDA to notify them of minor changes in a manufacturing process or its control. The sponsor is permitted to make the changes without waiting for FDA response, and the changes become part of the existing licensed process. (See PAS)

CBE-30 Changes being effected within 30 days; a regulatory submission sent to FDA to request minor changes in a manufacturing process or its control. FDA has 30 days in which to respond, after which the change is considered approved and the part of the existing licensed process. (See PAS)

CBER Center for Biologies Evaluation and Research at the FDA; CBER regulates vaccines, gene therapy, cellular products, allergenic extracts, antitoxins, antivenins, venoms, and blood and blood products (clotting factors and plasma derived products).

CCD Charge-coupled device; semiconductors connected so that the output of one serves as the input for the next (digital cameras, video cameras, and optical scanners all use CCD arrays); a light-sensitive integrated circuit that stores and displays the data for an image.

CCS Rotationally average collision cross-section; The CCS of an ion is used to calculate the area of an ion in the gas phase and expressed in Omega (see also Omega). Omega can be calculated empirically through the measurement of an ion's drift time as it passes through a gas filled drift tube or travelling wave ion guide (see also TWIG).

CD Circular dichroism; the absorption of left and right circularly polarized light, a property of molecules that are optically active. CD spectroscopy is a form of light-absorption spectroscopy that measures the difference in left and right circularly polarized light absorbed by a substance. The spectra can be analyzed to learn the different secondary structural types in a protein: alpha helix, parallel and antiparallel beta sheet, turn, and so on.

CDC Centers for Disease Control and Prevention (Atlanta, GA) an agency of the Department of Health and Human Services. CDC develops and applies disease prevention and control, promotes environmental health, and provides health education.