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We describe a new bonded-phase packing material, based upon surface-stabilised microparticulate silica, suitable for the rapid separation and purification of oligonucleotides. Columns packed with this material were demonstrated to give rapid separations of individual oligonucleotide species of up to 44 base units with high purity; agarose gel electrophoresis showed that the products were essentially single bands, with only trace quantities of the (n — 1)-mer present. Baseline resolution of the desired oligomer from (n±1)-mer was achieved under preparative loading conditions, where up to 200–300 μg of oligonucleotide could be separated. The separation was essentially independent of structure or sequence of the oligonucleotides. The retention mechanism of the oligonucleotides was investigated, and the results used to determine the optimum column configuration and separation conditions.

Homogeneous β-lactamase (β-lactam hydrolase, E.C. 3.5.2.6) from Enterobacter cloacae P99, an enzyme that has an important function in antibiotic resistance, was prepared using a single cation-exchange chromatographic step with CM-Sepharose fast-flow. A 6-g amount of the enzyme was isolated from 5 kg of cell paste, with 84% of the enzyme activity in the cell homogenate being recovered by the single cation-exchange step. The specific activity of the β-lactamase was 587 U/mg protein. The relative molecular mass of the enzyme was determined to be 45 kDa by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and the isoelectric point was 8.95.

Glycerokinase from the thermophilic bacterium Bacillus stearothermophilus was found to have an affinity for several reactive, triazine dyes. The enzyme was found to have a strong affinity for several dyes when the dyes were immobilised on an agarose support matrix. Matrices based on cellulose, or polymers of acrylic acid, were less suitable. The study of the effect of various physicochemical properties is described, including ligand concentration, pH, ionic strength, column dimensions and flow-rate. Glycerokinase could be bound to Procion blue MX-3G-Sepharose at low ionic strength (pH 7.5) and was most readily recovered by substrate elution. This matrix was used to purify to homogeneity the enzyme derived from 1 kg of bacteria, in three steps, with an overall recovery of 44%.