Selection synchrony of Chlamydomonas using the Rastgeldi Threshold Centrifuge

Abstract

The application of the Rastgeldi Threshold Centrifuge for the selection of cells for initiation of synchronous cultures was investigated using Chlamydomonas reinhardti as a test organism. The following main results were obtained: 1. 1. Centrifugation of a mixed population composed of zoospores and 6 h old cells obtained from light-dark synchronized cultures, gave almost complete separation of the two cell classes. 2. 2. Growth and sporulation of zoospores selected from continuous culture under constant conditions were compared with that of zoospores from light-dark synchronized cultures, with both cell types cultivated in continuous light. The selected cells were smaller than the light-dark synchronized ones, but after a period of growth and karyokinesis, all cells in both cultures divided, the resulting zoospore populations being equal. 3. 3. The synchrony of karyokinesis and sporulation of the selected cells subcultured in continuous light was as good as that obtained with the repeated light-dark synchronization method.