How can ordinary people distinguish legal black caviar from illegal? This is a burning issue since abundance of Russian sturgeon is 40 times lower than 15 years ago. Situation with great sturgeon (beluga) is even sadder.
      
      In Russia 50 fish farms have licenses to breed sturgeons; however, black caviar is produced at only several farms. Legal caviar is marked, but these marks are often forged.
      
      Russian geneticists found the solution – they suggested using fragments of mitochondrial DNA, which differ in various sturgeon species, and created a test system with a set of species-specific oligonucleotides.
      
      These markers then are used for PCR (polymerase chain reaction), which helps telling to what sturgeon species the fish belongs. All female sturgeons will be marked with a microchip and have a “genetic passport”, which later will help finding which fish produced caviar. Wrong DNA sample will show illegal caviar.
      
      Source: Science News