(American Geophysical Union, 2006-12-01)
Bernhard, Joan M.; Ostermann, Dorinda R.; Williams, David S.; Blanks, Jessica K.
The conventional method to distinguish live from dead benthic foraminifers uses Rose
Bengal, a stain that reacts with both live and dead cytoplasm. CellTracker Green CMFDA is a
fluorogenic probe causing live cells to fluoresce after proper incubation. To determine the more
accurate viability method, we conducted a direct comparison of Rose Bengal staining with
CellTracker Green labeling. Eight multicore tops were analyzed from Florida Margin (SE
United States; 248-751 m water depths), near Great Bahama Bank (259-766 m), and off the
Carolinas (SE United States; 220 m, 920 m). On average, less than half the Rose Bengal-stained
foraminifera were actually living when collected. Thus, while Rose Bengal can significantly
overestimate abundance, combined analyses of CellTracker Green and Rose Bengal can provide
insights on population dynamics and effects of episodic events. Initial stable isotope analyses
indicate that the CellTracker Green method does not significantly affect these important
paleoceanographic proxies.