Mass isolation and culture of sea urchin micromeres

A procedure is described for large-scale isolation of micromeres from 16-cell stage sea urchin embryos. One to two grams of >99% pure, viable micromeres (2.3 to 4.6 × 108 cells) are routinely isolated in a single preparation. In culture, these cells uniformly proceed through their normal development, in synchrony with micromeres in whole embryos, ultimately differentiating typical larval skeletal structures. The attributes of this procedure are: (a) the very early time of isolation of the cells, directly after the division that establishes the cell line; (b) the large yield of cells; (c) the purity of the preparation of cell; and (d) their synchronous development in culture through skeletogenesis. The procedure greatly aids in making sea urchin micromeres a favorable material for molecular analysis of development.