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A comparison of TO-PRO-1 iodide and 5-CFDA-AM staining methods for assessing viability of planktonic algae with
Elena Gorokhova1, Lisa Mattsson, Annica M Sundström
1Department of Applied Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden. elena.gorokhova@itm.su.se
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.
