title: Assessment of viability of yeast by flow cytometry using Light Green as vital dye exclusion.
abstract: A comparative study of two different staining methods for estimation of yeast's viability is assessed by microbial flow cytometry. Propidium iodide (PI) a well known nucleic-acid binding vital dye exclusion is compared with light green (LG), a cytoplasmic function related vital dye widely used in histological, histochemical and immunocytochemical staining. The yeast model used was heat-killed Candida guilliermondii cells. The stained heat-killed bacterial population showed on the dot-plot flow cytometer analysis, a clear separation towards the green-orange (350-600 nm) for LG, and orange-red (550-725 nm) for PI on the fluorescence spectrum-zone channels. Both dyes showed by non-parametric Kolmcgorov-Smirnov, 99% of probability of difference between heat-killed and live microorganism's histogram-population, with a D = ranking from 0.50-0.64 for LG to 0.91-0.98 for PI. Higher cost and carcinogenic risk when handling PI, make LG a better choice for flow cytometry yeast viability tests.
authors.affiliation: Departamento de Inmunoquímica Dr. Maximiliano Ruiz Castañeda, Instituto Nacional de Diagnóstico y Referencia Epidemiológicos, Dirección General de Epidemiología, SSA, Mexico.
authors.forename: F J
authors.initials: FJ
authors.lastname: Alvarado-Aleman
authors.forename: A
authors.initials: A
authors.lastname: Collazo-Ponce
authors.forename: J
authors.initials: J
authors.lastname: Kumate-Rodríguez
mesh_terms: D002175:Candida / Q000166:cytology* / Q000378:metabolism; D002463:Cell Membrane Permeability; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism; D008739:Methyl Green / Q000378:metabolism; D011419:Propidium / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes; D011419:Propidium; D008739:Methyl Green