Abstract
The fluorochrome primuline has been shown, by the micromanipulation of individual stained yeast cells, to be a useful stain for the determination of cell viability. A high correlation (96%) between non-fluorescence and viability was demonstrated for cells taken from young cultures, but the correlation decreased with increasing age of the cell suspension. The correlation between fluorescence and non-viability was 100% for yeast cells taken from any environment. Cells which were stained green after primuline treatment were inferred to be non-viable but an absolute correlation between non-viability and the “green” reaction could not be demonstrated. The staining technique was tested with animal cells (Paramecia, Amoebae) and the correlation between fluorescence and non-viability was confirmed. The staining result with a mammalian cell line was not confirmed by cell culture. The primuline technique for viable cell counts was primarily dependent on the loss of the selective permeability of the plasma membrane.