Determining the origin of catfish , squid and crabs in gelatinous products by genetic methods for the first time in Iran

Gelatin is an animal by-product obtained from the relative hydrolysis of collagen tissue in various parts of the animal body. Therefore, determining the solubility of the type of fish or marine used in gelatin, fat-soluble vitamins, unsaturated fatty acids and products containing them is necessary for some Islamic religions. Today in many gelatin products, especially supplements and gelatin capsules imported to Iran, different species of crabs, catfish and squid is used, which no way to identify them has been reported. Based on Bioinformatics studies and genes available in databases, specific primers were designed for qualitative trace crabs, catfish and squid in gelatin capsules and supplements. Then the PCR method was optimized. Finally, the extracted DNA was amplified with specific primers and detected on agarose gel. PCR reaction optimization was performed for specific primers for crab, catfish and squid, so bands 147, 124 and 112 bp were observed on the agarose gel, respectively. Specificity stability and reproducibility of the method for each pair of primers was confirmed. Then the PCR with extracted DNAs from the gelatin capsules were done with primers. Also, the sequencing of the amplified band with general aquatic primers confirmed the mentioned results. In this study, for the first time, with PCR method and designed specific primers can detect the crab, catfish and squid qualitatively in gelatin or products containing it, such as gelatin capsules, supplements and collagen, in a short time, before entering the country.