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Showing papers by "Rork Kuick published in 1991"


Journal ArticleDOI
TL;DR: The results clearly demonstrate that a defined temperature for first‐dimensional isoelectric focusing is a requirement for the reproducibility of 2‐D Electrophoresis.
Abstract: The effect of temperature, at which isoelectric focusing with immobilized pH gradients is performed, on spot positions and pattern quality in two-dimensional (2-D) electrophoresis was examined. Increased temperatures revealed improved 2-D patterns with respect to sample entry, resolution, and background staining. Focusing at 20 degrees C was superior to focusing at 10 and 15 degrees C. Even at 30 degrees C, a pattern of well-resolved polypeptide spots with a minimum amount of horizontal streaking at the basic end was observed. A computer-based analysis showed that a substantial proportion of polypeptides assumed altered positions in the 2-D pattern in relation to temperature. Mobility shifts of polypeptides were more variable on the neutral part than on the acidic or basic end. The mobility shifts were not restricted to one direction for all the spots whose migration was altered. However, for any given spot, the direction was the same with subsequent increments of temperature. The results clearly demonstrate that a defined temperature for first-dimensional isoelectric focusing is a requirement for the reproducibility of 2-D electrophoresis. After elimination of the cathodic drift, a major source of variability in 2-D patterns, associated with carrier ampholytes, temperature control becomes a critical parameter.

73 citations


Journal ArticleDOI
TL;DR: Results are given for 19, single‐Cell‐derived lymphoid clones in which the presence of a mutation had previously been established, each processed in duplicate, which demonstrates that the strategy is sensitive and efficient for detecting qualitative spot differences.
Abstract: An approach for the computer-assisted analysis of two-dimensional gels has been developed as a part of our laboratory information processing system (LIPS). This approach relies in part on an algorithm for the pairwise matching of protein spots. The matching process initially matches spots based on a cross-correlational measure of how well neighboring spots align. While this first pass correctly determines most spot correspondences and noncorrespondences, it can make errors. Higher accuracy is obtained by monitoring the consistency of spot match decisions in a second pass, which demands that neighboring spot pairs that align spatially must also have been found to match in the first pass. Pairwise comparisons of gels are, combined into n-way comparisons by matching spot lists of gels to “master” gel spot lists, which in turn are matched to higher level masters, resulting in a hierarchy of matched spots. After each pairwise match the results are reviewed and corrected with the assistance of a graphical match-editor. Results are given for 19, single-Cell-derived lymphoid clones in which the presence of a mutation had previously been established, each processed in duplicate. Only one of 46 spot changes failed to be detected, which demonstrates that the strategy is sensitive and efficient for detecting qualitative spot differences.

33 citations


Journal ArticleDOI
TL;DR: It is concluded that leukemic cells in infant ALL exhibit a unique pattern of phosphorylation of hsp27 expressed at a pre-B cell stage of differentiation.

32 citations


Journal ArticleDOI
TL;DR: The relational schema for each level of activity and the application development of LIPS, in terms of the relational database management system being used, is presented.
Abstract: A laboratory information processing system (LIPS) has been developed to provide support for various laboratory activities related to two-dimensional electrophoresis. In this paper we present the relational schema for each level of activity and the application development of LIPS, in terms of the relational database management system being used. We also discuss our experience with the current system.

11 citations