[Webinar] Mycotoxin On-Site Testing and Survey Results
You will discover:
- How to implement rapid on-site mycotoxin monitoring
- Overcoming some common on-site testing challenges
- Current mycotoxin threats to poultry, swine and ruminants worldwide
- Dangers posed by the presence of multiple mycotoxins
Frequently asked webinar questions and answers to:
- On Site Testing - Set Up & Challenges
- Accuracy & Reliability
On Site Testing - Set Up
How to conduct quick check for mycotoxins on commercial farms?
On site technologies like strip tests are suitable for a quick check for mycotoxins in raw materials. The set-up is very simple and fast. All you need is a room with standard power supply. Everything else can be provided by Romer Labs. The handling is very simple, as you need only few procedural steps to conduct the testing. An operator training takes less than 30 minutes. When completing the test you get straightforward results which can easily be documented.
How can I implement rapid in situ mycotoxin monitoring?
On site testing happens at raw material reception points. Feed millers and integrators already make a first quality assessment of raw materials before it enters the facility. This reception point is usually located at the gate of the facility, and provides a small place where parameters like humidity and nutritional concentrations are checked. This is the perfect place to implement mycotoxin on site testing.
How does the AgraVision™ reader work?
The AgraVision™ reader is Romer Lab's handheld lateral flow device used for the quantification of AgraStrip® mycotoxin and GMO products. It measures the intensity of the test line on the strip and can read up to two mycotoxin strips or four GMO strips simultaneously. Test results can easily be stored for hard copy documentation with the optional AgraVision™ printer strip.
On Site Testing - Challenges
Is there any on site immediate test or kits? What is the difference between strip tests and ELISA?
The two most popular on-site methods are strip tests and ELISA. Strip tests are designed to give results as soon as possible, though they can only process two samples at a time. They are therefore widely used at reception points of the supply chain of agricultural raw commodities. ELISA (enzyme-linked immunosorbent assay) test kits can test up to 44 samples simultaneously. In general, ELISA is the better option when you have 6 or more samples. Romer Labs offers a broad portfolio including both ELISA tests (AgraQuant®) and strip tests (AgraStrip®) to detect the most prevalent mycotoxins.
What are common on-site challenges, how to deal with them and how to help customers to be aware and understand them?
Testing at reception points is conducted in very rough and highly diverse environments. First advice is to keep an eye on temperature. Strip tests are immunologic tests, relying on the reaction of an antibody with a mycotoxin molecule. This reaction is highly influenced by temperature. Tests are developed to work at a defined temperature but on-site testing is conducted at locations with diverse ambient conditions. We advise to use an incubator with strip test to guarantee accurate results. Make sure you can clean your equipment. When testing on-site you often fight with dust and dirt. This can affect the optical system of the reader and eventually lead to drop in accuracy. Here we advise to use a robust device. You can easily open the AgraVision™ reader on its underside and clean the camera system with a brush.
What are the acceptable limits of mycotoxins for my sample?
Most countries have set maximum levels for mycotoxins in food and feed. The mycotoxins of most concern so far include aflatoxins (B1, B2, G1, G2 and M1), ochratoxin A, deoxynivalenol, fumonisins, T-2 toxin, HT-2 toxin, zearalenone and patulin. Other mycotoxins are gaining importance from a food and feed safety perspective and maximum levels are under discussion. See a listing of worldwide mycotoxin regulations by clicking on this Link.
How to perform an onsite strip test?
The AgraStrip® WATEX procedure consists of three easy steps: sample preparation, analysis and result documentation. First, mycotoxins are extracted from grain kernels into a liquid to make them accessible for analysis. You simply add your sample, a buffer bag and bottled water in a filter bag, shake it and let it settle. Filter and buffer bags are provided with the kit, so there is no need to purchase anything extra. The second step, the analysis of the sample takes place on a dipstick comparable with a pregnancy test. The strip test is put into the diluted sample extract and put in an incubator for 3 minutes. Then the analysis is completed and the result is quantified in a reader within seconds. Last but not least, we read and document the results. The display shows a concentration value like ppb, which allows you to assess the quality of your raw material.
How long does on site testing take to get the result?
The AgraStrip® WATEX test takes less than 10 minutes from sample preparation to final result.
How does sample preparation work without methanol?
Mycotoxins are extracted from grain kernels into a liquid to make them accessible for analysis. In the past, this was done with hazardous organic solvents like methanol. Romer Labs WATEX technology now allows for mycotoxin extraction using only water in combination with an environmental friendly buffer bag. This makes the purchase, handling and disposal of organic solvents obsolete.
Accuracy & Reliability
How to prevent obtaining false negative results, especially at low contamination levels
There are two main reasons for false negative or false positive results:
1. Matrix effects – matrix components in the sample extract may react with the antibody of the kit and thereby cause interferences. Hence, it is important to check with the manufacturer if the commodity is suitable for use in ELISA or not. Different manufacturers utilize different antibodies. Check with the manufacturer if the commodity matrix to be tested has been validated with the kit system.
2. Sampling error – mycotoxin contamination is unevenly distributed within a bulk. Insufficient sampling easily leads to false negative or false positive results. Use a proper sampling method.
How accurate are the results of field test analyzes?
Before the introduction of strip tests, ELISA was the technology of choice. Since strip tests are based on the same antibody technology accuracy is comparable. Strip tests are calibrated against accredited reference methods. Inaccuracy of rapid tests comes from matrix effects therefore validations of different commodities are highly important when dealing with strip tests.
What is the sensitivity (Limit of detection) and specificity of onsite tests?
Sensitivity (Limit of detection): Onsite strip tests are based on the same technology as well established ELISA tests. The sensitivity of strip tests is therefore comparable to ELISA tests. Find out more about LOD (Limit of detection) and quantitation ranges of Romer Labs test kits by clicking on the following Link.
Specificity: Romer Labs test kits are specific to one mycotoxin or a group of closely related mycotoxins. There is for example one kit to detect deoxynivalenol and another that detects aflatoxin B1, B2 G1 and G2. This group of aflatoxins is commonly referred to as total aflatoxins.
What is the reliability of rapid onsite tests?
Romer Labs develops test kits in compliance with test kit specifications of the USDA GIPSA. For more information on the specifications for each mycotoxin please visit the website of USDA/GIPSA.
Can we do rapid confirmation test to know the presence of mycotoxin in the ingredients or final feed?
We do not advise to test finished feed with onsite tests. The nutritional composition of different raw materials influences the test system. Test kit producers therefore need to calibrate their test for each of these different raw materials. When testing for feed, the tricky part is that the feed composition from raw commodities varies with market price, season and origin. The outcome is a huge variability in feed formulations. As there are so many feed formulations you would need an own calibration per feed type.
Is it possible to test for mycotoxins in DDGS samples?
It is possible to test DDGS samples with both AgraQuant® (ELISA) and AgraStrip® (LFDs) test kits provided by Romer Labs. Separate protocols (application notes) exist to test DDGS samples for the mycotoxin of interest.
Do you have quick test kits for mycotoxins being produced from putrefaction of animal protein sources?
Rapid onsite tests are designed to be used in agricultural raw material. All other commodities must be validated. Please contact a Romer Labs representative to learn more about commodity validations.
Do you have advice to test samples with low pH with ELISA?
When performing an ELISA it is important to check the pH of your sample extract. It needs to be between pH 6 - 8. Lower or higher pH would cause a difference in the binding behavior of the antibody. Hence, results would over- or underestimate.
How to conduct quick sampling of a 24 tons truckload without using automatic systems?
Regulatory bodies like the USDA or EU have established recommendations on how to do sampling most efficiently. GIPSA (grain inspection, packers and stockyards administration) has established sampling patterns for each type of carrier. It is recommended to use a grain probe or trier for manual sampling. For proper sampling of a 24 tons bulk, the European Union recommends to take at least 10 subsamples of 100 g each.
Does the use of multi-mycotoxin IACs affect the sensitivity of the assay in comparison to IAC for individual mycotoxins?
The performance of the column is amongst others dependent on the number of different antibodies present, in other words the number of mycotoxins. With increasing number of mycotoxins the IAC binding capacity will decrease due to the lower amount of each specific antibody present in the gel. This might have an effect on the sensitivity and the recoveries of the method.
How to detect masked mycotoxins?
The living plant once infected by a fungus producing mycotoxins might change the chemical structure of toxins and produce so-called masked mycotoxins. The plant can change the structure of the original mycotoxins and produce the so-called masked mycotoxins. Usually, a glucose molecule or a sulfate is conjugated to the mycotoxin leading to detoxification. Although these masked toxins do not further harm the plant, their toxicity to humans and animals might re-emerge with the cleavage of the added masking molecule in the gastrointestinal tract of mammals during digestion.
Romer Labs offers mycotoxin calibrant solutions that can be used in LC-MS/MS-based analyses. Both deoxynivalenol-3-glucoside as well as 13C labeled deoxynivalenol-3-glucoside are available.
What are the differences between onsite testing methods like strip tests or ELISA and HPLC?
Both ELISA and strip tests are antibody based technologies. Therefore, their results are comparable. The biggest challenge for such technologies is the matrix effect. Matrix components like proteins, fats or carbohydrates can influence the antigen antibody binding. A possible result is strong or weaker binding, that can lead to a greater result variability. Methods like HPLC or LC-MS/MS are chromatographic technologies based on the separation of analytes within a column. They are reference methods for mycotoxin analysis and considered to have higher reproducibility.