## Doctoral Dissertations

Spring 1993

Dissertation

Biochemistry

#### Degree Name

Doctor of Philosophy

Equilibrium electrophoresis is a new method that determines the apparent charge on macroions. The theory of equilibrium electrophoresis is summarized. The second generation device is described. Apparent charges, at various ionic strengths, measured by equilibrium electrophoresis are reported for pd(A)$\sb{20},$ pd(T)$\sb{20},$ pd(A)$\sb{20}$ $\cdot$ pd(T)$\sb{20},$ cytochrome c from horse heart, TA lysozyme mutant, TA(119/135) charge mutated lysozyme, and EDTA. The apparent charge of plasmid pBR322 from electrophoretic mobility and sedimentation velocity is reported. The results are compared to those expected according to the Record-Manning counterion condensation theory and the Debye-Huckel shielding theory. The apparent charges of the two ss DNA samples and the cytochrome c sample were equivalent to theoretical values within the expected experimental error. The validity of the basic equilibrium electrophoresis theory is argued. The range of usable experimental conditions for the present device is discussed. The sources of error in the current device are discussed, and suggestions for future models are given.