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Biomedical subjects

G P Rozing

Publications and source records attributed to G P Rozing.

5 recordsLinked to original sources
PubMed1991

Recovery of biologically active enzymes after HPLC separation.

The mass and activity recovery of eight different enzymes (two monomeric, six oligomeric) with molecular masses between 25,000 and 240,000 daltons were tested after HPLC separation on three different HPLC instruments (two with stainless steel and one with titanium flow paths). Most of the tested proteins are known to be sensitive to heavy metal ions. Eight wide pore, ion-exchange columns, two size-exclusion columns and two hydrophobic-interaction columns were used. Both stainless steel and glass column hardware were used in all three separation modes. The elution times were between 8 and 12 minutes. In almost all cases, the activity recovery was between 90% and 100% compared with a control sample incubated in the chromatographic elution buffer for the same time at the same temperature. A severe activity loss (about 30%) was observed with only one ion-exchange column and one enzyme. Neither the column hardware nor the material of the HPLC equipment had any negative effect on the activity recovery of the enzymes tested.

Alcohol Dehydrogenase↗
PubMed1989

Fast separation of biological macromolecules on non-porous, microparticulate columns.

The use of high-performance liquid chromatographic columns for the separation of proteins and nucleic acids is gradually increasing in biochemical laboratories. The efficiency of these columns for such separations has been much lower than that achievable for the separation of smaller molecules. Non-porous microparticulate packings are the logical answer one arrives at after consideration of the chromatographic behaviour of proteins. Non-porous stationary phases are described for the separation of proteins, peptides and nucleic acids. The stationary phases used are TSK-Gel NPR-C18, TSK-Gel NPR-DEAE, TSK-Gel NPR-SP and HYTACH MicroPell C18. A number of fundamental properties of columns based on these sorbents were evaluated, such as permeability, retention behaviour towards small and large molecules, load capacity and stability. Instrumental requirements for these columns are discussed and some applications described.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Advances in capillary electrochromatography.

This paper presents practical aspects of capillary electrochromatography (CEC). Preparation of capillary columns, including terminating frits and immobilization of the packed bed, is described in detail. Longevity and reproducibility of CEC columns is demonstrated. Instrumental aspects, sample introduction, sensitivity of detection, and gradient elution are discussed in detail. A number of examples that illustrate the versatility of CEC, in particular, for providing an isocratic separation alternative to conventional gradient separation in HPLC, are given.

Chromatography↗