Apart from fervent advice about how to preserve the family pet when Fido or Spot 'deanimates' (the Cryonics people - just like spiritualists - are so very uncomfortable with the word 'death') before the guys with the freezer arrive to make petsicles there is a fun paragraph about DNA preservation -
If your cryopreservation and reanimation proceeds without any problems, a DNA sample should be of little use. If you want your remains preserved under any circumstances and you are killed under circumstances that makes your remains hard to identify, a DNA sample could be useful to verify that the remains to be cryopreserved are really yours. Or you may simply want someone to be able to identify your remains so that there is no ambiguity or question about your identity when you are buried or cremated. Or if your body or the body of a loved-one is lost completely and you like the idea of a clone someday being constructed, the DNA could help. You may even want to save the DNA of your pet for possible future cloning. In some far-future scenarios it will be possible to reconstruct people from artifacts, such as the memories of you that are found in other people who have been reanimated and the physical records of your life, with DNA augmenting the process - although this is extreme science-fiction.Presumably the latter idea is a hit with devotees of quantum mysticism, homeopathy, astrology, 'matrix energetics', dowsing or 'psionic medicine', with their faith in water having a 'memory', coffee cups and rocks having a cosmic consciousness, ghosts (the dead, it seems, are still with us but "not in a familiar form", unsurprising if the cadaver's been cremated), reincarnation and similar mumbo-jumbo that has gained traction in parts of academia.