title: A comparison of TO-PRO-1 iodide and 5-CFDA-AM staining methods for assessing viability of planktonic algae with epifluorescence microscopy.
abstract: Two fluorescent dyes, TO-PRO-1 iodide and 5-CFDA-AM, were evaluated for LIVE/DEAD assessment of unicellular marine algae Brachiomonas submarina and Tetraselmis suecica. Epifluorescence microscopy was used to estimate cell viability in predetermined mixtures of viable and non-viable algal cells and validated using microplate growth assay as reference measurements. On average, 5-CFDA-AM underestimated live cell abundance by ~25% compared with viability estimated by the growth assay, whereas TO-PRO-1 iodide provided accurate viability estimates. Furthermore, viability estimates based on staining with TO-PRO-1 iodide were not affected by a storage period of up to one month in -80°C, making the assay a good candidate for routine assessment of phytoplankton populations in field and laboratory studies.
authors.affiliation: Department of Applied Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden. elena.gorokhova@itm.su.se
authors.forename: Elena
authors.initials: E
authors.lastname: Gorokhova
authors.forename: Lisa
authors.initials: L
authors.lastname: Mattsson
authors.forename: Annica M
authors.initials: AM
authors.lastname: Sundström
mesh_terms: D002470:Cell Survival; D000460:Chlorophyta / Q000502:physiology*; D005452:Fluoresceins / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000379:methods*; D009930:Organic Chemicals / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods*
chemical_list: C505935:5-carboxyfluorescein diacetate acetoxymethyl ester; D005452:Fluoresceins; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C405903:TO-PRO-1