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Biomedical subjects

R R Walters

Publications and source records attributed to R R Walters.

27 records · Page 2Linked to original sources
PubMed1987

Dual-column determination of albumin and immunoglobulin G in serum by high-performance affinity chromatography.

High-performance affinity chromatography was used for the simultaneous determination of albumin and immunoglobulin G in serum. Two columns in series, the first containing immobilized anti-albumin antibodies and the other containing protein A for binding immunoglobulin G, were eluted separately at pH 3 by means of a column-switching system. This method gave results in good agreement with commercially available methods, while requiring only 2 microliter of serum and 6.0 min per cycle. It was shown that albumin and immunoglobulin G were selectively retained, with little interference from other components, including immunoglobulins A and M.

Chromatography, Affinity↗
PubMed1985

Affinity chromatographic examination of a retention model for macromolecules.

Plots of log k' vs. log (1/[mobile phase modifier]) were made for a monovalent and a divalent solute using affinity chromatography. Some of the plots were curved and all exhibited slopes (Z values) of less than the theoretical integer values. It was shown that this was an expected result when lower forms of the solute were present, e.g., a divalent solute adsorbed monovalently.

Chromatography, Affinity↗
PubMed1984

Protein separations on reversed-phase high-performance liquid chromatography minicolumns.

The resolution of cytochrome c, bovine serum albumin and ovalbumin on reversed-phase columns under gradient elution conditions was found to be constant or to improve as column length was decreased from 45 to 6.3 mm. The resolution remained constant even when the column length decreased to 1.6 mm. Recovery of protein in the first gradient cycle was improved by the use of short columns.

Animals↗
PubMed1984

Protein diffusion coefficient measurements by laminar flow analysis: method and applications.

Laminar flow in an open tube leads to solute band spreading. This process is opposed by radial diffusion. The translational diffusion coefficient of a solute can be calculated from the band dispersion, tube length, and flow rate. No calibration is necessary. A simple apparatus was used to measure the diffusion coefficients of several small solutes and 18 proteins. Most results were within +/- 10% of literature values. Each determination required 7-90 min, depending on the magnitude of the diffusion coefficient. The amount of protein needed was approximately 25 micrograms. The diffusion coefficient data were useful for the estimation of molecular weights.

Chemical Phenomena↗
PubMed1983

Determination of immunoglobulins in blood serum by high-performance affinity chromatography.

High-performance affinity chromatography columns were prepared by immobilizing protein A from Staphylococcus aureus on 10-microns diol-bonded silica. Immunoglobulin-containing samples were injected into the column at pH 7 and eluted by stepwise changes to pH 3. Immunoglobulin G, A, and M standards were tested, but only a small fraction of the latter two was retained on the column. Analysis of 3-microliters samples of reference blood sera without pretreatment was performed using immunoglobulin G standards. Good agreement was observed between the immunoglobulin G concentrations measured by this method and by radial immunodiffusion. Chromatography of albumin and electrophoresis of retained serum fractions showed no interference by non-specific adsorption. Chromatographic analysis times were 4 min or less.

Chromatography, Affinity↗