As a result, the cost of testing increases while the time it takes to get results increases. There is a need to develop alternative, faster and more affordable methods for contamination detection.
“We have proposed a simple method for determining the composition of sausages and other meat-containing products. Our development makes it possible to detect chicken and pork in samples quickly and without using unnecessary devices”, ?? Anatoly Zherdev, head of the RSF project said. Anatoly Zherdev is a Ph. in Biology and is a lead researcher in the Laboratory of Immunochemistry of the RAS Biotechnology Research Center (Moscow).
First, the authors isolated DNA from the samples, added short tagged nucleotide primer sequences (biotin and fluorescein), and recombinant polymerase amplification reagent. This process is carried out at constant temperature, without special tools for more complex amplification. As a result, in just 15 minutes, the number of copies of the DNA fragment enclosed by the two primers increased significantly. In this development, the gene for one of the chicken and pig mitochondrial proteins was used to generate DNA.
The resulting solution is dripped onto the test strip with streptavidin molecules that can selectively bind biotin in the detection region. As a result, the required DNA was attached to the band. The scientists then added gold nanoparticles with immobilized antibodies to fluorescein ?? After the nanoparticles bind, the color in the test strip appears. Such a multilayer “sandwich” reduces the risk of false results and increases the reliability of the test.
Biochemists tested the system on samples provided by partners from the Federal Center for Research on Food Systems VM Gorbatov: minced meat with different concentrations of chicken, pork and beef. , as well as meat products cooked to government standards. The scientists compared two variants of DNA extraction: standard long-term and rapid.
With the reduction of sample preparation time, the brightness of the test strip color decreases slightly. However, three minutes was enough to reliably detect the color change in the detection area and draw conclusions about the admixture?? if there is a case of adding chicken or pork when it is not supposed to follow the recipe.
“All of our analysis phases take just 33 minutes. It doesn’t require complicated equipment or expensive reagents,” says Anatoly Zherdev.