Dataset: Alexandrium cell counts

"Whole Cell" preserved samples. For the “Whole Cell” A. catenella water samples collected during the surveys, 2 Liters of seawater were drained from Niskin bottles into pre-rinsed bottles and sieved thru 20µm Nitex. The concentrated particulate material retained on the sieve was backwashed with filtered seawater (<15µm) into 15ml centrifuge tubes to a final volume of 14ml and preserved with formalin to a final concentration of 5%. After storage at 4oC for no longer than 36 hours, the tubes were centrifuged for 5 min (5000 x g), formalin was removed by aspiration leaving the pellet, replaced with 100% cold methanol, and stored at -20C for later analysis.

Enumeratio"n of the WC samples followed the methods developed by Anderson et al (2005a) using a species-specific oligonucleotide probe (NA-1) conjugated to a Cy3 fluorochrome and visualized with epi-fluorescence microscopy.

“Live" Count samples. To obtain quick estimates of Alexandrium sp. concentrations while at sea, 10 L of seawater from a surface 10L Niskin bottle was sieved and concentrated to 14ml.   A 1ml aliquot of the concentrate was loaded into a Sedgewick- Rafter counting chamber and enumerated using standard light microscopy.