Even though Jurassic Park, the movie and the book, are both fantasy thrillers, people often confuse them for actual science. Among these confusions is whether or not "dino DNA" could survive for millions of years within mosquitoes that have preserved in amber. JP says yes: science continues to say no, with new research saying "Almost definitely no."
A team of researchers from the University of Manchester recently reported their studies of sub-fossil insects enclosed in copal. These are insects trapped in tree resin that is too young to have turned into amber. Using both non-destructive (keep the specimen intact) and destructive (grind those specimens into soup) means, they extracted as much DNA as they could from some stingless bees preserved in the copal.
Good news: they found DNA! Bad news: it's extremely small pieces of DNA, and the biggest pieces are from bacteria.
So, with the most advanced methods which exist today, on specimens only ~10,600 years old, DNA of organisms inside the precursor of amber does not appear to preserve. The likelihood that DNA could survive for 1000 times longer is really, really, low. The scientific basis of Jurassic Park is fantasy, not science fiction, and definitely not science fact.