Sampling


For toxin analysis:
Water samples (minimum 100 mL) should be collected and stored on wet ice (4oC) out of the light. Amber glass containers with PTFE-lined caps are preferred since certain hydrophobic toxin congeners may adsorb to plastics. However, due to breakage concerns during shipping, polyethylene terephthalate glycol (PETG) containers can be used in place of glass bottles.  Unless specified, we will measure the total concentration of each toxin class requested by lysing all cells in the sample and measuring the total toxin concentration.  If particulate (intracellular) toxin and free (extracellular) toxin measurements are requested, we will concentrate the samples onto glass fiber filters ($10 processing fee/sample) and extract toxin off of the filter and from the filtrate and analyze them separately.  Note that once a sample has been frozen, it is only possible to determine total toxins since freeze-thawing will lyse the cells.  Samples should be processed or frozen within five (5) days of collection in order to minimize toxin decay.

For SPATT (solid phase adsorption toxin tracking) analysis, after retrieval from the water body, the bags should be thoroughly rinsed in distilled or deionized water, then stored in DI water at 4oC if analysis will be conducted within one week or at -20oC for long-term storage.

For shellfish samples, customers should provide the laboratory with frozen or lyophilized tissue homogenates.

For DNA analysis:

Customers can send water samples (minimum 100 mL) in glass or plastic (HDPE or PETG) bottles as described above or they can send filtered samples stored folded in microcentrifuge tubes or aluminum foil.  If whole water is mailed to the lab, we will concentrate the sample onto glass fiber filters and extract total DNA from the filtered sample ($10 processing fee/sample).  Water samples must never be frozen, because upon thawing the cells will lyse and release their DNA into solution, which will not be retained by filtering.  If customers choose to concentrate their own samples and send us filters, they should be mailed frozen on ice.  The sample volume filtered must also be provided in order for us to accurately calculate gene copies/mL using QPCR.  Please note that samples should be processed as soon as possible and withing five (5) days in order to minimize cell lysis and DNA degradation.

For Microscopy:

If requested, we will take photographs of samples under the microscope and report the cyanobacterial genera and their relative abundances (e.g., Oscillatoria sp. was most abundant, with Microcystis sp. observed at low densities).  These photographs are helpful in determining which cyanotoxins may be present based on the following table:

Cyanobacteria_toxin_table_for_website