When are Rapid Tests Used?

Rapid tests are a relatively fast and inexpensive mostly qualitative way to determine the presence of cyanotoxins. These are only to be used as a screening method to determine the presence or absence of a class of cyanotoxins and not be used in lieu of quantitative lab testing. Rapid kits are used in the field and take an hour or less to complete. These tests are often used in conjunction with laboratory testing to confirm the magnitude (or quantity/quantitative) of cyanotoxins because their measurement range, from lowest detection limit to maximum detection, are often not comparable with advisory levels. These tests also have a higher rate of false negatives and positives than lab based testing so results should be considered with some skepticism and recommend that these tests are used in conjunction with lab based testing to confirm results at least 50% of the time.

Who can use Rapid Tests?

 Rapid tests do not require previous lab experience and can be successfully used by trained volunteers. Rapid tests are relatively simple to use but have limitations. Thus, some training, including practice performing the rapid tests, is recommended in order to maximize the method's effectiveness.

Considerations Before Use

• Steps that require cell lysis or breaking apart of cells to release toxins will likely add time but required to appropriately measure the presence of toxins.

• Cannot be used with scum or algal mat samples because these samples are too dense.

• Are heat-sensitive, keep kits in a cool location or indoor temperatures.

• Must be used in freshwater (i.e low salinity water).

• Results are semi-qualitative often produce presence/absence data with an unknown but high error rate.

PRODUCT DISCLAIMER: 

The CA Water Boards FHAB Program does not endorse use of kits from any particular manufacturer. This guidance is intended to improve the performance of these tests when organizations prefer to use these kits due to limited resources for monitoring. Please be aware of additional considerations prior to use and contact your FHAB Regional Coordinator for questions:

• Some field test kits do not include a lysis step with chemicals and/or repeated freeze and thaw cycles to obtain a “total” concentration of toxins in your sample. These kits are insufficient to measure the presence or absence of toxins in your sample. The total concentration of toxins in your sample includes the proportion of toxins stored in the cells and dissolved in the water that was collected, without breaking up cells a portion of the toxins will not be detected.

• The range of detection by each kit is important to note so that the lowest detection and highest detection can be compared to the state advisory levels. For example, the microcystins advisory levels range from 0.8 ug/L to greater than 20 ug/L. Recently reviewed kits describe a detection range from approximately 0.5 to 2 ug/L and up to 10 ug/L. For this circumstance the toxin detection range is somewhat comparable to the two lowest advisory levels and may not provide sufficient accuracy in the measurement to inform public health risk. These kits are a good screening tool to prompt posting of the lowest advisory level (caution sign) and confirmation testing by laboratory tests that provide quantitative results.  

Steps to Rapid Test Monitoring

1. Write a monitoring plan (template available below) and send to your FHAB regional coordinator the plan to provide technical assistance.

2. Request training on rapid tests if you have not previously used them from your FHAB regional coordinator.

3. Obtain materials (supply list below).

4. At the monitoring site, fill in the field data sheet and use the rapid tests.

5. Report results via Water Reporter or our online Report System.

Comparing Rapid Test Options for Recreational Waters**:

*Lightdeck does not currently sell a chemical lysing agent (which releases cyanotoxins from the cyanotoxin cells for accurate measurement). Using three freeze-thaw cycles is currently recommended. This adds time to the process.

** Rapid tests are available for finished and/or source water but outside of the scope of guidance materials.

What is a test reader and when should I use one?

Eurofin Abraxis: 

Cyanotoxin strips provide results in the form of a colored line. The lines correspond to a cyanotoxin concentration but reading and interpreting this line with the naked eye can be subjective. Cyanotoxin Strip Scanners make strip reading more precise by digitally scanning the strip and quantifying its results. These instruments increase the cost of monitoring but may produce more reliable data.

Lightdeck:  

Lightdeck cartridges require a Lightdeck Mini instrument to analyze cartridges. These instruments require a plug-in external power source and computer. Thus, many people run samples at a site with power, such as a lab, but they have been used in cars with an appropriate port. 

Training Videos:

Planning Documents

Printable Documents