title: A simple colony-formation assay in liquid medium, termed 'tadpoling', provides a sensitive measure of Saccharomyces cerevisiae culture viability.
abstract: Here we describe the first high-throughput amenable method of quantifying Saccharomyces cerevisiae culture viability. Current high-throughput methods of assessing yeast cell viability, such as flow cytometry and SGA analysis, do not measure the percentage viability of a culture but instead measure cell vitality or colony fitness, respectively. We developed a method, called tadpoling, to quantify the percentage viability of a yeast culture, with the ability to detect as few as one viable cell amongst ~10(8) dead cells. The most important feature of this assay is the exploitation of yeast colony formation in liquid medium. Utilizing a microtiter dish, we are able to observe a range of viability of 100% to 0.0001%. Comparison of tadpoling to the traditional plating method to measure yeast culture viability reveals that, for the majority of Saccharomyces species analyzed there is no significant difference between the two methods. In comparison to flow cytometry using propidium iodide, the high-throughput method of measuring yeast culture viability, tadpoling is much more accurate at culture viabilities < 1%. Thus, we show that tadpoling provides an easy, inexpensive, space-saving method, amenable to high-throughput screens, for accurately measuring yeast cell viability.
authors.affiliation: Department of Biology, Johns Hopkins University, Baltimore, MD, 21218, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA.
authors.forename: Aaron Z
authors.initials: AZ
authors.lastname: Welch
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Koshland
mesh_terms: D015169:Colony Count, Microbial / Q000379:methods; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000254:growth & development*; D012680:Sensitivity and Specificity; D013997:Time Factors
keywords: culture viability; desiccation tolerance; flow-cytometry; high-throughput method