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K Hebenbrock

Publications and source records attributed to K Hebenbrock.

3 recordsLinked to original sources

Single strand conformational polymorphism using capillary electrophoresis with two-dye laser-induced fluorescence detection.

Capillary electrophoresis (CE), using a replaceable polymer matrix and two-dye laser-induced fluorescence has been applied to single strand conformational polymorphism (SSCP). Two-dye laser-induced fluorescence has been used for improved strand identification over a single-dye approach. Conditions suitable in the capillary format for rapid separation and high resolution have been explored. The influence of separation parameters such as temperature and matrix composition on separation in SSCP was first determined. Short analysis times allowed for fast screening of optimal separation conditions of the sample. Based on these results, the two strands of a standard 255 bp fragment of the lacI gene were resolved within 25 min with replaceable linear polyacrylamide as a separation matrix. The method was then applied to the detection of different mutations, in the presence of wild type, of a 276 bp fragment of the insulin-like growth factor 1-binding protein 1 (IGF1-BP3) gene.

Amino Acid Sequence↗

Sequence dependent migration behavior of double-stranded DNA in capillary electrophoresis.

Capillary electrophoresis (CE) with a replaceable linear polyacrylamide (LPA) sieving matrix was used to examine sequence-dependent migration of double-stranded DNA fragments. It has been found that DNA conformational effects were significant under high electric field separations, especially using high resolution matrices. Compared to linear DNA-ladder standards, both anomalously slow and rapid DNA fragments were observed, with the degree of anomalous migration depending on the electric field strength, polymer concentration, column temperature, and background electrolyte (denaturants, sodium and magnesium ions, DNA-intercalating dyes). By selecting a combination of electrophoretic conditions (e.g. 3% T LPA, elevated capillary temperature, lower electric field strength and addition of DNA intercalating dyes), molecular weight dependent separations were closely restored.

Bacteriophage phi X 174↗

Analysis of plasmid-DNA and cell protein of recombinant Escherichia coli using capillary gel electrophoresis.

Plasmid DNA prepared from cultivation samples of recombinant Escherichia coli was analyzed by capillary gel electrophoresis. We used this method to control the genetic stability during a fed-batch culture. The plasmid DNA and a standard DNA mixture with molecular weights in the size range of 3000-22,000 base pairs (bp) were analyzed in capillaries that were filled with solutions of non-cross-linked polyacrylamide. With this method the plasmid DNA from recombinant E. coli cultivation samples was analyzed within 30 min. Separation parameters such as gel concentration, capillary length and current were optimized for that purpose. The method was modified to allow the analysis of proteins. Crude cell lysate samples could be screened for the protein pattern within 15 min in sodium dodecyl sulfate-polyacrylamide filled capillaries. The method was also used to verify product purity after the down-stream process.

Capillary Action↗