Biochip array technology provides a testing platform that enables the simultaneous determination of multiple analytes with a single sample. It uses miniaturised assay procedures, which enables the reduction of sample/reagent consumption and improves the cost-effectiveness of the tests.
The technology is based upon ELISA principles of sandwich and competitive immunoassays.
Multiple specific ligands (antibodies or antigens) are attached at pre-defined discrete test regions on the surface of the biochip. Analyte in a sample leads to binding of conjugate labelled with Horseradish Peroxidase (HRP). The addition of signal reagent leads to generation of a light signal.
Assay specific reagents supplied in the kit are applied to the biochip surface along with prepared samples. After incubation period immuno-reactions generate chemiluminescent signal, which is inversely proportional to the concentration of the analyte in the sample. Using the Evidence Investigator Analyser, an integrated camera simultaneously detects the light signals emitted by each test site of the array. Images and numerical data are automatically processed and stored.
In 2011 46 border rejections were raised in the EU for residues of veterinary medical products, 25 of which were for the anthelmintic drug Ivermectin. These rejections have highlighted the need for a rapid and reliable screening method for many border inspection points and import authorities as vigilance must be increased to ensure that foods containing these drugs are not allowed to enter the food chain.
Anthelmintics are drugs that act against internal parasites of animals such as tapeworms, liver flukes and round worms that can cause helminthic infections. The use of anthelmintic drugs can greatly improve livestock production. Anthelmintic drugs administered to ruminants to treat parasitic worm infestation are considered a risk to food safety if they enter the food chain. Treatment of the infected animal with the wrong drugs, incorrect dosage or insufficient withdrawal period of the drugs are contributing to antibiotic resistance (AR) as residues of these compounds can remain in the milk or tissue of treated animals.
There are several classes of anthelmintic drugs such as benzimidazoles, avermectins, albendazoles, moxidectin and levamisole with maximum residue levels established for the majority of compounds.
The anthelmintics testing array can detect 25 anthelmintic compounds from a single sample detecting both parent and metabolite forms of the compounds. These include albendazole sulphoxide and albendazole – 2 aminosulphones, both of which are the main residues detected in tissue matrices irrespective of whether animals were dosed with netobimim, albendazole or albendazole sulphoxide.
The generic Avermectin biochip can detect residues of Ivermectin, Abamectin, Doramectin, Emamectin benzoate and Eprimomectin, all or some of which have been noted as marker residues in food by the European Union, CODEX, Canada and the US.
A simple QuEChERS method will allow for a unified sample preparation for all compounds with preparation, analysis and semi-quantitative determination in less than four hours. Internal studies carried out using corned beef, jerky and raw meats indicate this is a suitable screening tool that complies with all regulatory requirements and correlates well with LCMS/MS confirmatory analysis. Enhanced sensitivity was determined and ranged from 0.15ppb to 6.5ppb in beef muscle and 0.3ppb – 2ppb in milk.
The biochip testing platform uses the world’s only multi-analyte semi quantitative drug residue analyser; the Evidence Investigator. This multiplex platform is also available for an extensive list of antibiotics and growth promoting compounds using sample matrices including muscle, liver/kidney, seafood, milk, honey, urine and animal feed. The multiplex testing format will reduce cost, run time and labour requirements, all of which guarantees a faster turnaround time for results along with a higher sample throughput.
For further information on the Randox anthelmintics array or any of our products, please contact us or visit our website.