Biomaterial Database

Studies on polydisperse systems using an air-driven ultracentrifuge: application to phosphatidylcholine vesicles. 1979

R G Clarke, and G R Eagle, and G J Howlett

A high-speed air-driven ultracentrifuge (Airfuge) has been used to determine the molecular weight and effective specific volume of phosphatidylcholine vesicles. The method used to determine the effective specific volume involved varying the solution density until zero sedimentation of the vesicles occurred. The value obtained for the effective specific volume of 0.9885 ml/g agrees well with previously reported values. The determination of the molecular weight of the vesicles is based on a method in which the fraction of vesicles remaining in an upper fraction of the solution column is compared with the values obtained using standard proteins. The values obtained for the molecular weight of the vesicles range from 1.7 X 10(6) to 2.3 X 10(6) and are in good agreement with results obtained using the analytical ultracentrifuge and with previously reported results. Possible effects due to the polydispersity of the solute are assessed using theoretical calculations and the possibility of using the Airfuge for the study of other polydisperse systems is discussed.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008567	Membranes, Artificial	Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.	Artificial Membranes,Artificial Membrane,Membrane, Artificial
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010713	Phosphatidylcholines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a CHOLINE moiety.	Choline Phosphoglycerides,Choline Glycerophospholipids,Phosphatidyl Choline,Phosphatidyl Cholines,Phosphatidylcholine,Choline, Phosphatidyl,Cholines, Phosphatidyl,Glycerophospholipids, Choline,Phosphoglycerides, Choline
D014461	Ultracentrifugation	Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)