Differential electrophoretic separation of cells and its effect on cell viability

An electrophoretic separation method was applied to the separation of cells. To determine the efficiency of the separation, it was necessary to apply existing methodology and develop new methods to assess the characteristics and functions of the separated subpopulations. Through appropriate application of the widely used isoelectric focusing procedure, a reproducible separation method was developed. Cells accumulated at defined pH and 70-80% remained viable. The cells were suitable for further biologic, biochemical and immunologic studies

Multiple Cdk1 Inhibitory Kinases Regulate the Cell Cycle during Development

AbstractThe Wee kinases block entry into mitosis by phosphorylating and inhibiting the activity of the mitotic cyclin-dependent kinase, Cdk1. We have found that the various Xenopus Wee kinases have unique temporal and spatial patterns of expression during development. In addition, we have isolated and characterized a new Wee1-like kinase, Xenopus Wee2. By both in vivo and in vitro tests, Xenopus Wee2 functions as a Wee1-like kinase. The previously isolated Wee1-like kinase, Xenopus Wee1, is expressed only as maternal gene product. In contrast, Xenopus Wee2 is predominantly a zygotic gene product, while the third Wee kinase, Xenopus Myt1, is both a maternal and zygotic gene product. Concurrent with the changing levels of these Cdk inhibitory kinases, the pattern of embryonic cell division becomes asynchronous and spatially restricted in the Xenopus embryo. Interestingly, once zygotic transcription begins, Xenopus Wee2 is expressed in regions of the embryo that are devoid of mitotic cells, such as the involuting mesoderm. In contrast, Xenopus Myt1 is expressed in regions of the embryo that have high levels of proliferation, such as the developing neural tissues. The existence of multiple Wee kinases may help explain how distinct patterns of cell division arise and are regulated during development